John W. Weeks (April 11, 1860-July 12, 1926) was an American politician in the Republican Party. He served as a United States Representative for Massachusetts from 1905 to 1913, as a United States Senator from 1913 to 1919, and as Secretary of War from 1921 to 1925.
Weeks was born and raised in Lancaster, New Hampshire. He received an appointment to the United States Naval Academy, graduating in 1881, and served two years in the United States Navy.
Weeks made a fortune in banking during the 1890s, after co-founding the Boston financial firm Hornblower and Weeks in 1888. With his financial well-being assured, Weeks became active in politics, first at a local level in his then-home of Newton, Massachusetts (he served as alderman in 1899-1902 and as mayor in 1903-04), then on the national scene.
As a member of the United States House of Representatives and United States Senate, Weeks was notable mostly for his contributions to banking and conservation legislation.
Despite his defeat for re-election to the Senate in 1918, Weeks remained an active and influential participant in the national Republican Party. He was an early supporter of the nomination of Warren G. Harding for President in 1920, and when Harding became President, he named Weeks to his cabinet.
As Secretary of War, Weeks was a competent, honest, and respected administrator and adviser, who guided the Department of War through its post-World War I downsizing. Weeks' hard work and long hours led to a stroke in April 1925, which led in turn to his resignation as Secretary in October of that year.
Weeks died several months later, at his summer home in Mount Prospect, New Hampshire.
Weeks' son, Charles Sinclair Weeks, was Secretary of Commerce during the Eisenhower administration.
Weeks' cousin, Edgar Weeks, was a U.S. Representative from Michigan. His grand-uncle, also named John Wingate Weeks (1781-1853), was a Major in the U.S. Army during the War of 1812 and a U.S. Representative from New Hampshire.