Watson McMillan Hayes (Chinese: 赫士; pinyin: Hèshì, November 23, 1857 – August 2, 1944) was an American Presbyterian missionary and educator in China.

With the backing of Yuan Shikai, he also published Shandong's first successful newspaper (Shantung Times, Chinese: 山东时报; pinyin: Shāndōng Shíbào) and petitioned the Qing court to grant a holiday on Sundays for government schools and colleges;[5] Shandong College was closed on Sundays right from the start.

[4] However, by the end of 1901, Hayes and six Chinese Christian teachers he had brought with him had resigned already[4] over disagreements regarding the policy of mandatory Confucius worship for students of the college.

[7] However, after theological conflicts arose in the college due to the fundamentalist-modernist controversy, Haynes was asked to resign in 1919.

[9] His trial in China was the topic of an article ("The Brainwashing of John Hayes", written by Frederic Sondern, Jr) published in Reader's Digest (July 1955) and a television drama of the same title (teleplay by George Bruce, aired on TV Reader's Digest by ABC on 7 November 1955) in which Hayes was portrayed by the actor Vincent Price.