Digital Realty Trust, Inc. Common Stock We have entered into a sales agreement (as may be amended from time to time, the “sales agreement”) with BofA Securities, Inc., BNP Paribas Securities Corp., BTIG,LLC, Capital One Securities, Inc., Citigroup Global Markets Inc., Deutsche Bank Securities Inc., Huntington Securities, Inc., ING Financial Markets LLC, JefferiesLLC, J.P. Morgan Securities LLC, Mizuho Securities USA LLC, Morgan Stanley& Co. LLC, MUFG Securities Americas Inc., Raymond James& Associates, Inc., RBCCapital Markets, LLC, Santander US Capital Markets LLC, Scotia Capital (USA) Inc., TD Securities (USA) LLC, Truist Securities, Inc., UBS Securities LLC and WellsFargo Securities, LLC, or collectively, the Agents, and the Forward Sellers and Forward Purchasers (each as defined below), relating to the offer and sale of shares of ourcommon stock, $0.01 par value per share (“common stock”), having an aggregate sales price of up to $7,500,000,000 from time to time under this prospectus supplementand the accompanying prospectus through the Agents, acting as our sales agents, or, if applicable, through the Forward Sellers, acting as agents for the relevant ForwardPurchasers, in connection with any forward sale agreements. Upon entry into the sales agreement, we terminated our prior at-the-market program. At the time of suchtermination, approximately $569.9million remained unsold under such program. Sales of the shares, if any, under this prospectus supplement and the accompanying prospectus may be made by means of ordinary brokers’ transactions at market prices,in negotiated transactions or in transactions that are deemed to be “at-the-market” offerings as defined in Rule 415 under the Securities Act of 1933, as amended,including sales made to or through a market maker other than on an exchange, in block transactions or by any other method permitted by law, at prices related to theprevailing market prices or at negotiated prices subject to certain minimum prices. Each of the Agents and the Forward Sellers has agreed to use its commerciallyreasonable efforts consistent with its normal trading and sales practices to solicit offers to purchase our common stock, under the terms and subject to the conditions setforth in the sales agreement. We may instruct any Agent or Forward Seller, as applicable, not to sell our common stock if the sales cannot be effected at or above the pricedesignated by us in any placement notice. We, or any of the Agents or Forward Sellers, as applicable, may suspend the offering of shares of our common stock at anytime upon proper notice and subject to other conditions. We also may sell shares of common stock to each of the Agents, as principal for its own account, at a price to be agreed upon at the time of sale. If we sell shares of ourcommon stock to any of the Agents, as principal, we will enter into a separate terms agreement with such Agent, and, to the extent required by applicable law, we willdescribe the terms agreement in a separate prospectus supplement or pricing supplement. We will pay each of the Agents acting as our sales agent a commission that will not exceed, but may be lower than, 2.0% of the gross sales price per share of shares soldthrough it as our agent under the sales agreement. The compensation to each Forward Seller will be a mutually agreed commission in the form of a reduction to the initialforward price under the related forward sale agreement that will not exceed, but may be lower than, 2.0% of the gross sales price of the borrowed shares sold throughsuch Forward Seller during the applicable forward hedge selling period for such shares (which gross sales price will be adjusted for daily accruals based on a floatinginterest rate and specified amounts related to expected dividends on shares of our common stock if an “ex-dividend” date occurs during such forward hedge sellingperiod). See “Plan of Distribution” and “Use of Proceeds” in this prospectus supplement. None of the Agents or Forward Sellers is required to sell any specific number or dollar amount of shares of our common stock but each will use its reasonable efforts,subject to the terms of the sales agreement, to sell the shares offered as instructed by us (with respect to the Agents) and all the shares borrowed by the relevant ForwardPurchaser pursuant to the sales agreement (with respect to the Forward Sellers). The offering of our common stock pursuant to the sales agreement will terminate uponthe earlier of (1)the sale of all common stock subject to the sales agreement (including shares sold by us to or through the Agents and borrowed shares sold through theForward Sellers) or (2)termination of the sales agreement. The sales agreement contemplates that, in addition to the issuance and sale by us of shares of our common stock to or through the Agents as our sales agents, we mayenter into separate forward sale agreements (each, together with any related pricing supplement, a “forward sale agr