6-K

SECURITIES AND EXCHANGECOMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Private IssuerPursuant to Rule 13a-16 or 15d-16 of the Securities Exchange Act of 1934

July 2024

Commission File Number: 001-37925

GDS Holdings Limited

(Registrant’s name)

F4/F5, Building C, SunlandInternational

No. 999 Zhouhai Road

Pudong, Shanghai 200137

People’s Republicof China

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F x   Form 40-F ¨

EXHIBITS

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

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Exhibit 99.1

Hong KongExchanges and Clearing Limited, The Stock Exchange of Hong Kong Limited (the “Hong Kong Stock Exchange”) and HongKong Securities Clearing Company Limited take no responsibility for the contents of this announcement, make no representation as to itsaccuracy or completeness and expressly disclaim any liability whatsoever for any loss howsoever arising from or in reliance upon thewhole or any part of the contents of this announcement.

GDS HoldingsLimited** (the “Company”) is controlled through weighted voting rights. Shareholders and prospective investors shouldbe aware of the potential risks of investing in a company with a weighted voting right, or WVR, structure. Particularly, the WVR beneficiary,whose interests may not necessarily be aligned with those of our shareholders as a whole, will be in a position to exert significantinfluence over the outcome of shareholders’ resolutions, irrespective of how other shareholders vote. Our American depositary shares,each representing eight of our Class A ordinary shares, are listed on the Nasdaq Global Market in the United States under the symbolGDS.

GDSHoldings Limited

萬國數據控股有限公司*

(Acompany controlled through weighted voting rights and incorporated in the Cayman Islands with limited liability under the name GDS HoldingsLimited and carrying on business in Hong Kong as GDS WanGuo Holdings Limited)

(StockCode: 9698)

CHANGEOF CUSTODIAN BANK

We hereby announce that we were recently informed that JPMorgan Chase Bank, N.A., the depositary for our American depositary shares (the “ADS(s)”), will change its custodian to HSBC Hong Kong with effect from August 12, 2024. As a result, from August 5, 2024 to August 12, 2024, we will not be able to facilitate the conversion between our ADSs and our ordinary shares registered on our Cayman Islands share registrar and the conversion between our ADSs and our ordinary shares registered on our Hong Kong share registrar, Computershare Hong Kong Investor Services Limited.

Save for the abovementioned impacts, the change of custodian will not affect the trading of our securities on The Nasdaq Global Market or on the Hong Kong Stock Exchange during the migration period.

Hong Kong, July 19, 2024

As atthe date of this announcement, the board of directors of the Company comprises Mr. William Wei Huang as the chairman, Mr. Sio Tat Hiangas the vice-chairman, Mr. Satoshi Okada, Mr. Bruno Lopez, Mr. Gary J. Wojtaszek and Mr. Liu Chee Ming as directors, and Mr. Lim Ah Doo,Ms. Bin Yu, Mr. Zulkifli Baharudin, Mr. Chang Sun and Ms. Judy Qing Ye as independent directors.