John Hammill (October 14, 1875 – April 6, 1936) served three terms as the 24th Governor of Iowa from 1925 to 1931.

In August 1923, Governor Nathan E. Kendall was sidelined because of a heart condition, which led to speculation that he would resign before the end of his term, thus leaving Hammill as Iowa's governor.

[5] Kendall did not seek re-election in 1924, and Hammill announced his candidacy for the post.

Hammill won the 1924 Republican gubernatorial nomination, and defeated James C. Murtagh in the general election in a landslide.

He died on April 6, 1936, of a heart attack in a Minneapolis hotel room[2][7] and was buried in Britt.