This summary highlights information contained elsewhere in this prospectus. Because this is only a summary, it does not contain all the information that may be important to you. To understand this offering fully, you should read this entire prospectus, the registration statement of which this prospectus forms a part and the documents incorporated by reference herein carefully, including the information set forth under the heading “Risk Factors” and our financial statements. Unless otherwise indicated or the context otherwise requires, all references in this prospectus to “Iris Energy,” “we,” “us,” “our,” “its,” and the “Company” refer to the registrant and its consolidated subsidiaries.

We are a leading owner and operator of institutional-grade, highly efficient proprietary Bitcoin mining data centers powered by 100% renewable energy. Our mining operations generate revenue by earning Bitcoin through a combination of block rewards and transaction fees from the operation of our specialized computers called ASICs and exchanging these Bitcoin for fiat currencies such as USD or CAD on a daily basis.

We have been mining Bitcoin since 2019. We liquidate all the Bitcoin we have mined daily and therefore do not currently have any Bitcoin held on our balance sheet. We target development of Bitcoin mining facilities in regions where there are low-cost, abundant and attractive renewable energy sources.

We have ownership of our proprietary data centers and electrical infrastructure, including freehold and long-term leasehold land. This provides us with security and operational control over our assets. Long-term asset ownership also allows our business to benefit from more sustainable cash flows in comparison with miners that rely upon third-party hosting services or short-term land leases which may be subject to termination rights, profit sharing arrangements and/or potential changes to contractual terms such as pricing. We also focus on grid-connected power access which not only helps to ensure we are able to utilize a reliable, long-term supply of power, but also provides us with the ability to support the energy markets in which we operate (for example, through potential participation in demand response, ancillary services provision and load management in deregulated markets such as Texas).

In January 2020, we acquired our first site in Canal Flats, located in British Columbia, Canada (“BC”), from PodTech Innovation Inc. and certain of its related parties. This is our first operational site and has been operating since 2019. In addition, we have constructed, and continue to construct, additional proprietary data centers at our other BC sites in Mackenzie and Prince George. Our Mackenzie site has been operating since April 2022, and we are in the process of expanding the operating capacity at our Mackenzie site. Our Prince George site commenced operations in September 2022.

Each of our sites in British Columbia are connected to the British Columbia Hydro and Power Authority (“BC Hydro”) electricity transmission network and have been 100% powered by renewable energy since commencement of operations (currently approximately 97% sourced from clean or renewable sources as reported by BC Hydro and approximately 3% sourced from the purchase of RECs). We are also engaged in construction activities at our site in Childress, located in the renewables-heavy Panhandle region of Texas, U.S.

On September 23, 2022, we entered into the Purchase Agreement and a registration rights agreement (the “Registration Rights Agreement”) with B. Riley Principal Capital II. Pursuant to the Purchase Agreement, we have the right to sell to B. Riley Principal Capital II up to $100.0 million of our Ordinary shares, subject to certain limitations and conditions set forth in the Purchase Agreement, from time to time during the term of the Purchase Agreement. Sales of our Ordinary shares pursuant to the Purchase Agreement, and the timing of any sales, are solely at our option, and we are under no obligation to sell any securities to B. Riley Principal Capital II under the Purchase Agreement. In accordance with our obligations under the Registration Rights Agreement, we have filed the registration statement that includes this prospectus with the SEC to register under the Securities Act the resale by B. Riley Principal Capital II of up to 25,000,000 Ordinary shares, including (i) up to 24,801,826 Ordinary shares that we may elect, in our sole discretion, to issue and sell to B. Riley Principal Capital II, from time to time from and after the Commencement Date (defined below) under the Purchase Agreement, and (ii) 198,174 Ordinary shares that we expect to issue to B. Riley Principal Capital II on or prior to the Commencement (defined below) in consideration for its irrevocable commitment to purchase our Ordinary shares that we may, in our sole discretion, direct it to make from time to time after the date of this prospectus pursuant to the Purchase Agreement.

Upon the initial satisfaction of the conditions to B. Riley Principal Capital II’s purchase obligations set forth in the Purchase Agreement (the “Commencement”), including that the registration statement of which this prospectus forms a part be declared effective by the SEC, we will have the right, but not the obligation, from time to time at our sole discretion over the 24-month period beginning on the date the Commencement occurs (the “Commencement Date”), to direct B. Riley Principal Capital II to purchase a specified number of our Ordinary shares (each, a “Purchase”), not to exceed: (i) in the case of a “VWAP Purchase-Type A,” the lesser of (a) 2,000,000 of our Ordinary shares and (b) 10.0% of the total aggregate number (or volume) of our Ordinary shares traded on Nasdaq during the applicable Purchase Valuation Period (as defined below) for such Purchase; and (ii) in the case of a “VWAP Purchase-Type B,” the lesser of (a) 2,000,000 of our Ordinary shares and (b) 20.0% of the total aggregate number (or volume) of our Ordinary shares traded on Nasdaq during the applicable Purchase Valuation Period (as defined below) for such Purchase (in each case, the lesser of such number of shares, the “Purchase Maximum Amount” and such specified number of shares to be purchased by the Holder in such Purchase, adjusted to the extent necessary to give effect to the applicable Purchase Maximum Amount and certain additional limitations set forth in the Purchase Agreement, the “Purchase Share Amount”), by timely delivering written notice to B. Riley Principal Capital II (each, a “Purchase Notice”) prior to 9:00 a.m., New York City time, on any trading day (each, a “Purchase Date”), so long as (a) the closing sale price of our Ordinary shares on Nasdaq on the trading day immediately prior to such Purchase Date is not less than $1.00, subject to adjustment as set forth in the Purchase Agreement (such price, as may be adjusted from time to time in accordance with the Purchase Agreement, the “Threshold Price”), and (b) all of our Ordinary shares subject to all prior purchases effected by us under the Purchase Agreement with Purchase Share Delivery Dates (as defined below) prior to the Purchase Date have been received by B. Riley Principal Capital II prior to the time we deliver such Purchase Notice to B. Riley Principal Capital II.

The per share purchase price that B. Riley Principal Capital II is required to pay for our Ordinary shares in a Purchase effected by us pursuant to the Purchase Agreement, if any, will equal to ninety-seven percent (97%) of the volume weighted average price of our Ordinary shares (the “VWAP”), calculated in accordance with the Purchase Agreement, for the period (the “Purchase Valuation Period”) beginning at the official open (or “commencement”) of the regular trading session on Nasdaq on the applicable Purchase Date for such Purchase, and ending at the earliest to occur of (i) 3:59 p.m., New York City time, on such Purchase Date or such earlier time publicly announced by the trading market as the official close of the regular trading session on such Purchase Date, (ii) such time that the total aggregate number (or volume) of our Ordinary shares traded on Nasdaq during such Purchase Valuation Period (calculated in accordance with the Purchase Agreement) reaches the applicable share volume maximum amount for such Purchase (the “Purchase Share Volume Maximum”), calculated by dividing (a) in the case of a VWAP Purchase-Type A, (1) the applicable Purchase Share Amount for such Purchase by (2) 0.10 and (b) in the case of a VWAP Purchase-Type B, (1) the applicable Purchase Share Amount for such Purchase by (2) 0.20, and (iii) to the extent that the Company elects in the applicable Purchase Notice that the Purchase Valuation Period will also be determined by the Minimum Price Threshold (as defined below), such time that the trading price of our Ordinary shares on Nasdaq during such Purchase Valuation Period (calculated in accordance with the Purchase Agreement) falls below the applicable minimum price threshold for such Purchase specified by us in the Purchase Notice for such Purchase, or if we do not specify a minimum price threshold in such Purchase Notice, a price equal to 75.0% of the closing sale price of our Ordinary shares on the trading day immediately prior to the applicable Purchase Date for such Purchase (the “Minimum Price Threshold”).

In the event that we elect in the applicable Purchase Notice that the Purchase Valuation Period will also be determined by the Minimum Price Threshold, for purposes of calculating the volume of our Ordinary shares traded during a Purchase Valuation Period, as well as the VWAP for a Purchase Valuation Period, the following transactions, to the extent they occur during such Purchase Valuation Period, are excluded: (x) the opening or first purchase of the Ordinary shares at or following the official open of the regular trading session on Nasdaq on the applicable Purchase Date for such Purchase and (y) the last or closing sale of the Ordinary shares at or prior to the official close of the regular trading session on Nasdaq on the applicable Purchase Date for such Purchase.

In the event that we do not elect in the applicable Purchase Notice that the Purchase Valuation Period will also be determined by the Minimum Price Threshold, the calculation of the volume of our Ordinary shares traded during a Purchase Valuation Period and the VWAP for a Purchase Valuation Period will exclude the following transactions, to the extent they occur during such Purchase Valuation Period: (x) the opening or first purchase of the Ordinary shares at or following the official open of the regular trading session on Nasdaq on the applicable

Purchase Date for such Purchase, (y) the last or closing sale of the Ordinary shares at or prior to the official close of the regular trading session on Nasdaq on the applicable Purchase Date for such Purchase, and (z) all trades of the Ordinary shares on Nasdaq during such Purchase Valuation Period at a price below the applicable Minimum Price Threshold for such Purchase.

In addition to the regular Purchases described above, after the Commencement, we will also have the right, but not the obligation, subject to the continued satisfaction of the conditions set forth in the Purchase Agreement, to direct B. Riley Principal Capital II to purchase, on any trading day, including the same Purchase Date on which a regular Purchase is effected (if any, although we are not required to effect an earlier regular Purchase on such trading day), a specified number of our Ordinary shares (each, an “Intraday Purchase”), not to exceed: (i) in the case of an Intraday VWAP Purchase-Type A, the lesser of (a) 2,000,000 of our Ordinary shares and (b) 10.0% of the total aggregate volume of our Ordinary shares traded on Nasdaq during the applicable “Intraday Purchase Valuation Period” (determined in the same manner as for a regular Purchase) for such Intraday Purchase; and (ii) in the case of an Intraday VWAP Purchase-Type B, the lesser of (a) 2,000,000 of our Ordinary shares and (b) 20.0% of the total aggregate volume of our Ordinary shares traded on Nasdaq during the applicable Intraday Purchase Valuation Period (in each case, such lesser number of shares, the “Intraday Purchase Maximum Amount” and such specified number of shares, adjusted to the extent necessary to give effect to the applicable Intraday Purchase Maximum Amount, the “Intraday Purchase Share Amount”), by the delivery to B. Riley Principal Capital II of an irrevocable written purchase notice, after 10:00 a.m., New York City time (and after the Purchase Valuation Period for any prior regular Purchase (if any) and the Intraday Purchase Valuation Period for the most recent prior Intraday Purchase effected on the same Purchase Date (if any) have ended), and prior to the earlier of (a) 3:30 p.m., New York City time, on such Purchase Date and (b) such time that is exactly thirty minutes immediately prior to the official close of the primary (or “regular”) trading session on the Trading Market (or, if our Ordinary shares are then listed on an Eligible Market (as defined below), on such Eligible Market) on such Purchase Date if the Trading Market (or such Eligible Market, as applicable) has previously publicly announced that the official close of the primary (or “regular”) trading session on the Trading Market (or on such Eligible Market, as applicable) on such Purchase Date shall be earlier than 4:00 p.m., New York City time, on such Purchase Date (each, an “Intraday Purchase Notice”), so long as (i) the closing sale price of our Ordinary shares on the trading day immediately prior to such Purchase Date is not less than the Threshold Price and (ii) all of our Ordinary shares subject to all prior Purchases and all prior Intraday Purchases by B. Riley Principal Capital II prior to the relevant Purchase Date under the Purchase Agreement have been received by B. Riley Principal Capital II prior to the time we deliver such Intraday Purchase Notice to B. Riley Principal Capital II.

The per share purchase price for our Ordinary shares that we elect to sell to B. Riley Principal Capital II in an Intraday Purchase pursuant to the Purchase Agreement, if any, will be calculated in the same manner as in the case of a regular Purchase (including the same fixed percentage discounts to the applicable VWAP as in the case of a regular Purchase, as described above), provided that the VWAP for each Intraday Purchase effected on a Purchase Date will be calculated over different periods during the regular trading session on Nasdaq on such Purchase Date, each of which will commence and end at different times on such Purchase Date.

There is no upper limit on the price per share that B. Riley Principal Capital II could be obligated to pay for our Ordinary shares we may elect to sell to it in any Purchase or any Intraday Purchase under the Purchase Agreement. In the case of Purchases and Intraday Purchases effected by us under the Purchase Agreement, if any, all share and dollar amounts used in determining the purchase price per share of our Ordinary shares to be purchased by B. Riley Principal Capital II in a Purchase or an Intraday Purchase (as applicable), or in determining the applicable maximum purchase share amounts or applicable volume or price threshold amounts in connection with any such Purchase or Intraday Purchase (as applicable), in each case, will be equitably adjusted for any reorganization, recapitalization, non-cash dividend, share split, reverse share split or other similar transaction occurring during any period used to calculate such per share purchase price, maximum purchase share amounts or applicable volume or price threshold amounts.

From and after Commencement, we will control the timing and amount of any sales of our Ordinary shares to B. Riley Principal Capital II. Actual sales of our Ordinary shares to B. Riley Principal Capital II under the Purchase Agreement will depend on a variety of factors to be determined by us from time to time, including, among other things, market conditions, the trading price of our Ordinary shares and determinations by us as to the appropriate sources of funding for our business and operations.

We may not issue or sell any share of our Ordinary shares to B. Riley Principal Capital II under the Purchase Agreement which, when aggregated (i) with all other Ordinary shares then beneficially owned by

B. Riley Principal Capital II (as calculated pursuant to Section 13(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and Rule 13d-3 thereunder), would result in B. Riley Principal Capital II beneficially owning more than 4.99% of the outstanding Ordinary shares (the “Beneficial Ownership Limitation”), or (ii) with all other Ordinary shares then beneficially owned by B. Riley Principal Capital II and its affiliates, would exceed a regulatory threshold that would trigger an approval being required from a governmental authority (including, without limitation, the Foreign Acquisitions and Takeovers Act 1975 (Cth)) (a “Regulatory Approval”).

The net proceeds to us from sales that we elect to make to B. Riley Principal Capital II under the Purchase Agreement, if any, will depend on the frequency and prices at which we sell our Ordinary shares to B. Riley Principal Capital II. We expect that any proceeds received by us from such sales to B. Riley Principal Capital II will be used to fund our growth initiatives (including hardware purchases and acquisition and development of data center sites and facilities), and for working capital and general corporate purposes.

There are no restrictions on future financings, rights of first refusal, participation rights, penalties or liquidated damages in the Purchase Agreement or Registration Rights Agreement, other than a prohibition on entering into any other “committed equity fund,” “equity line of credit” or similar transaction as described in the Purchase Agreement during the term of the Purchase Agreement. See “Plan of Distribution (Conflict of Interest)” for more information regarding this restriction.

B. Riley Principal Capital II has agreed that none of B. Riley Principal Capital II, its sole member or any entity managed or controlled by B. Riley Principal Capital II or its sole member, or any of their respective officers, will engage in or effect, directly or indirectly, for its own account or for the account of any other of its affiliates, any short sales of our Ordinary shares or hedging transaction that establishes a net short position in our Ordinary shares during the term of the Purchase Agreement.

The Purchase Agreement will automatically terminate on the earliest to occur of (i) the first day of the month following the 24-month anniversary of the Commencement Date, (ii) the date on which the Holder shall have purchased from us under the Purchase Agreement our Ordinary shares for an aggregate gross purchase price of $100.0 million, (iii) the date on which our Ordinary shares shall have failed to be listed or quoted on Nasdaq or another U.S. national securities exchange identified as an “eligible market” in the Purchase Agreement (“Eligible Market”) for a period of one trading day, (iv) the 30th trading day after the date on which a voluntary or involuntary bankruptcy proceeding involving our company has been commenced that is not discharged or dismissed prior to such trading day, and (v) the date on which a bankruptcy custodian is appointed for all or substantially all of our property or we make a general assignment for the benefit of creditors.

We have the right to terminate the Purchase Agreement at any time after Commencement, at no cost or penalty, upon five trading days’ prior written notice to B. Riley Principal Capital II. We and B. Riley Principal Capital II may also agree to terminate the Purchase Agreement by mutual written consent, provided that no termination of the Purchase Agreement will be effective during the pendency of any Purchase or any Intraday Purchase that has not then fully settled in accordance with the Purchase Agreement. Neither we nor B. Riley Principal Capital II may assign or transfer our respective rights and obligations under the Purchase Agreement or the Registration Rights Agreement, and no provision of the Purchase Agreement or the Registration Rights Agreement may be modified or waived by us or B. Riley Principal Capital II.

As consideration for B. Riley Principal Capital II’s commitment to purchase our Ordinary shares at our direction upon the terms and subject to the conditions set forth in the Purchase Agreement, we expect to issue, on or prior to the Commencement (as defined herein), 198,174 Commitment Shares to B. Riley Principal Capital II. Furthermore, we have agreed to reimburse B. Riley Principal Capital II for the reasonable legal fees and disbursements of B. Riley Principal Capital II’s legal counsel in an amount not to exceed $125,000 in connection with the execution of the Purchase Agreement and Registration Rights Agreement, as well as certain ongoing disbursements of its legal counsel up to $7,500 per quarter in connection with B. Riley Principal Capital II’s ongoing due diligence and review of deliverables.

The Purchase Agreement and the Registration Rights Agreement contain customary representations, warranties, conditions and indemnification obligations of the parties. Copies of the agreements have been filed as exhibits to the registration statement that includes this prospectus and are available electronically on the SEC’s website at www.sec.gov.

We do not know what the purchase price for our Ordinary shares will be and therefore cannot be certain as to the number of shares we might issue to B. Riley Principal Capital II under the Purchase Agreement after the Commencement Date. As of November 1, 2022, there were 54,982,916 Ordinary shares outstanding. Although the Purchase Agreement provides that we may sell up to $100.0 million of our Ordinary shares to the B. Riley Principal Capital II, 25,000,000 Ordinary shares are being registered under the Securities Act for resale by the Holder under this prospectus, which represents (i) the 198,174 Commitment Shares that we expect to issue on or prior to the Commencement to B. Riley Principal Capital II in consideration for its irrevocable commitment to purchase our Ordinary shares that we may, in our sole discretion, direct it to make from time to time after the date of this prospectus pursuant to the Purchase Agreement and (ii) up to 24,801,826 of our Ordinary shares that may be issued to B. Riley Principal Capital II from and after the Commencement Date, if and when we elect to sell shares to B. Riley Principal Capital II under the Purchase Agreement. If all of the shares offered for resale by B. Riley Principal Capital II under this prospectus were issued and outstanding as of the date hereof, such shares would represent approximately 31.3% of outstanding Ordinary shares as of November 1, 2022.

The number of our Ordinary shares ultimately offered for resale by B. Riley Principal Capital II through this prospectus is dependent upon the number of Ordinary shares, if any, we elect to sell to B. Riley Principal Capital II under the Purchase Agreement from and after the Commencement Date. The issuance of our Ordinary shares to B. Riley Principal Capital II pursuant to the Purchase Agreement will not affect the rights or privileges of our existing shareholders, except that the economic and voting interests of each of our existing shareholders will be diluted. Although the number of Ordinary shares that our existing shareholders own will not decrease, the Ordinary shares owned by our existing shareholders will represent a smaller percentage of our total outstanding Ordinary shares after any such issuance.

Investing in our Ordinary shares involves substantial risk. You should carefully consider all the information in this prospectus prior to investing in our Ordinary shares. There are several risks related to our business and our ability to leverage our strengths and execute our strategies described elsewhere in this prospectus that are described under “Risk Factors” elsewhere in this prospectus. Among these important risks are risks associated with the following:

Please see “Risk Factors” in our Annual Report on Form 20-F for the fiscal year ended June 30, 2022 (“Form 20-F”), our Report on Form 6-K filed on November 21, 2022 and our other filings with the SEC, which are incorporated by reference herein for a discussion of these and other factors you should consider before making an investment in our Ordinary shares.

We were originally incorporated under the laws of New South Wales, Australia, on November 6, 2018 as “Iris Energy Pty Ltd” an Australian proprietary company (ACN 629 842 799). On October 7, 2021, we converted into a public company named “Iris Energy Limited” under Australian law and on November 19, 2021, we closed our initial public offering in the United States. Our principal executive offices are located at Level 12, 44 Market Street, Sydney, Australia, and our telephone number is +61 2 7906 8301. We maintain a website at https://irisenergy.co/. Information on our website is not incorporated by reference into or otherwise part of this prospectus. You should rely only on the information contained in this prospectus when making a decision as to whether to invest in the Ordinary shares.

As a company with less than $1.07 billion in revenue during our last fiscal year, we qualify as an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012 (“JOBS Act”). For so long as we remain an emerging growth company, we are eligible to utilize the following provisions of the JOBS Act that contain exceptions from disclosure and other requirements that otherwise are applicable to companies that conduct initial public offerings and file periodic reports with the SEC. These provisions include, but are not limited to:

We will remain an emerging growth company until the first to occur of (i) June 30, 2027, (ii) the last day of the fiscal year in which we have total annual gross revenue of at least $1.07 billion or (iii) the last day of the fiscal in which we are deemed to be a “large accelerated filer,” as defined in the Exchange Act, which means the market value of our Ordinary shares that are held by non-affiliates exceeds $700 million as of the last business day of the second financial quarter of such financial year; or, if it occurs before any of the foregoing dates, the date on which we have issued more than $1 billion in non-convertible debt over a three-year period.

We have elected to utilize certain of the reduced disclosure obligations in this prospectus and may elect to utilize other reduced reporting requirements in our future filings with the SEC. As a result, the information that we provide to our shareholders may be different than what you might receive from other public reporting companies in which you hold equity interests.

Under Section 107(b) of the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards until such time as those standards apply to private companies. Given that we currently

report and expect to continue to report under the International Financial Reporting Standards (“IFRS”) as issued by the International Accounting Standards Board (“IASB”), we will not be able to avail ourselves of this extended transition period and, as a result, we will adopt new or revised accounting standards on the relevant dates on which adoption of such standards is required by the IASB.

We qualify as a “foreign private issuer” under U.S. securities laws. Even after we no longer qualify as an emerging growth company, as long as we qualify as a foreign private issuer under the Exchange Act, we will be exempt from compliance with certain laws and regulations of the SEC, including:

As a foreign private issuer, we are also permitted to follow home country corporate governance practices instead of certain corporate governance practices required by the Nasdaq for U.S. domestic issuers. While we intend to follow most Nasdaq corporate governance listing standards, we intend to follow Australian law for certain corporate governance practices in lieu of Nasdaq corporate governance listing standards as follows:

We intend to take all actions necessary for us to maintain compliance as a foreign private issuer under the applicable corporate governance requirements of the Sarbanes-Oxley Act, the rules adopted by the SEC and the Nasdaq corporate governance rules and listing standards.

Because we are a foreign private issuer, our officers, directors and principal shareholders are not subject to short-swing profit and insider trading reporting obligations under Section 16 of the Exchange Act. They will, however, be subject to the obligations to report changes in share ownership under Section 13 of the Exchange Act and related SEC rules.

We may utilize these exemptions until such time as we are no longer a foreign private issuer. We would cease to be a foreign private issuer at such time as more than 50% of our outstanding voting securities are directly or indirectly held of record by U.S. holders and any one of the following is true: (i) the majority of our executive officers or directors are U.S. citizens or residents; (ii) more than 50% of our assets are located in the United States; or (iii) our business is administered principally in the United States.

Both foreign private issuers and emerging growth companies are also exempt from certain more stringent executive compensation disclosure rules. Thus, even if we no longer qualify as an emerging growth company but remain a foreign private issuer, we will continue to be exempt from the more stringent compensation disclosures required of companies that are not emerging growth companies and will continue to be permitted to follow our home country practice on such matters.

For additional information, see “Item 3.D. Key Information—Risk Factors—Risks Related to Being a Foreign Private Issuer—As a foreign private issuer, we are exempt from a number of rules under the U.S. securities laws and are permitted to file less information with the SEC than a U.S. company” and “Item 3.D. Key Information—Risk Factors—General Risk Factors—We are an “emerging growth company” under the JOBS Act and will be able to avail ourselves of reduced disclosure requirements applicable to emerging growth companies” in our Form 20-F, incorporated herein by reference.

For additional information concerning the offering, see “Plan of Distribution (Conflict of Interest).”