William High Keim (June 13, 1813 – May 18, 1862) was a Republican member of the U.S. House of Representatives from Pennsylvania, as well as a general in the Union Army during the American Civil War.

In 1837, he succeeded his cousin Daniel M. Keim as captain of the Grays and became major general of the Fifth Division of the Pennsylvania Volunteers in 1842.

His arrest and imprisonment eventually led to an important Federal case on the suspension of habeas corpus.

[4] Initially, Keim enlisted in the Union Army for a term of 3 months and, due primarily to his political ties to Governor Andrew Curtin,[citation needed] he was commissioned as a major general of Pennsylvania Volunteers on April 20, 1861.

[2] As the war lengthened and it became evident that a quick victory was not in sight, Keim decided to re-enlist, this time for a term of 3 years.