ZTO 6-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16 UNDER

THE SECURITIES EXCHANGE ACT OF 1934

For the month of July 2025

Commission File Number: 001-37922

ZTO Express (Cayman) Inc.

Building One, No. 1685 Huazhi Road

Qingpu District

Shanghai, 201708

People’s Republic of 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  ¨

Exhibit Index

Exhibit 99.1 – Announcement — Date of Board Meeting

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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.

Date: July 31, 2025

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Exhibit99.1

HongKong Exchanges and Clearing Limited and The Stock Exchange of Hong Kong Limited take no responsibility for the contents of this announcement,make no representation as to its accuracy or completeness and expressly disclaim any liability whatsoever for any loss howsoever arisingfrom or in reliance upon the whole or any part of the contents of this announcement.

Underour weighted voting rights structure, our share capital comprises Class A ordinary shares and Class B ordinary shares. Each Class A ordinaryshare entitles the holder to exercise one vote, and each Class B ordinary share entitles the holder to exercise 10 votes, respectively,on all matters that require a shareholder’s vote. Shareholders and prospective investors should be aware of the potential risksof investing in a company with a weighted voting rights structure. Our American depositary shares, each representing one of our ClassA ordinary shares, are listed on the New York Stock Exchange in the United States under the symbol ZTO.

ZTOExpress (Cayman) Inc.

中通快遞（開曼）有限公司

(Acompany controlled through weighted voting rights and incorporated in the Cayman Islands with limited liability)

(StockCode: 2057)

DATEOF BOARD MEETING

The board of directors (the “Board”) of ZTO Express (Cayman) Inc. (the “Company”) hereby announces that a meeting of the Board will be held on Tuesday, August 19, 2025 (Beijing time) for the purpose of, among others, approving (i) the Company’s unaudited financial results for the second quarter ended June 30, 2025 and its publication; and (ii) the Company’s unaudited interim results for the six months ended June 30, 2025 and its publication.

The Company will release its unaudited financial results for the second quarter ended June 30, 2025 and for the six months ended June 30, 2025 on Wednesday, August 20, 2025 (Beijing time), before the trading hours of The Stock Exchange of Hong Kong Limited.

The Company’s management team will host an earnings conference call at 8:30 P.M. on Tuesday, August 19, 2025 (U.S. Eastern Time), which is 8:30 A.M. on Wednesday, August 20, 2025 (Beijing Time).

Dial-in details for the earnings conference call are as follows:

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A replay of the earnings conference call may be accessible through Tuesday, August 26, 2025 by dialing the following numbers:

A live and archived webcast of the earnings conference call will also be available at the Company’s investor relations website at http://zto.investorroom.com.

Hong Kong, July 31, 2025

As atthe date of this announcement, the Board comprises Mr. Meisong LAI as the chairman and executive director, Mr. Jilei WANG and Mr. HongqunHU as executive directors, Mr. Xing LIU and Ms. Di XU as non-executive directors, Mr. Frank Zhen WEI, Mr. Qin Charles HUANG, Mr. HermanYU, Mr. Tsun-Ming (Daniel) KAO and Ms. Fang XIE as independent non-executive directors.

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