William Hewitt Baker (April 29, 1831 – February 11, 1910) was a U.S. Representative from Kansas.

William Hewitt Baker was born near Centerville, Pennsylvania, and grew up to become a prominent figure in Kansas.

In 1878, Baker moved to Lincoln County, Kansas, where he became a farmer and rancher.

Baker was a teacher and moved to Iowa in 1859 to become the principal of the public schools in Council Bluffs.

William Hewitt Baker, a member of the Populist Party, was elected to three consecutive terms in the U.S. House of Representatives, serving from March 4, 1891, to March 3, 1897, as part of the Fifty-second, Fifty-third, and Fifty-fourth Congresses.