William Gannaway Brownlow (August 29, 1805 - April 29, 1877) was Governor of Tennessee from 1865 to 1869 and a Senator from Tennessee from 1869 to 1875. Serving during Reconstruction following the American Civil War, Brownlow was strongly pro-Union and is considered one of the state's most hated governors.

Brownlow's election as governor is regarded by many as having been rigged. The South had just surrendered, much of the state had been under a Union military occupation government, and there was still much confusion. As ex-Confederate soldiers and Confederate sympathizers were barred from voting, most of the electorate was confined to the eastern part of the state, where there had never been much slavery practiced and secession was generally never popular or accepted.

Tennessee was not officially readmitted to the union until July 2, 1866; even then it was the first ex-Confederate state to be officially readmitted. Brownlow was re-elected by a still-reduced electorate in 1867; he resigned in February, 1869 to accept election to the United States Senate by the state legislature, the method used prior to the ratification of the Seventeenth Amendment.

Also known as "Parson" Brownlow or "The Fighting Parson", he made his way to East Tennessee as a travelling (itenerant) Methodist preacher. He travelled from town to town, giving fire and brimstone speeches to anyone who would listen. Perhaps somewhat surprisingly, given his ardent pro-Union views, Brownlow was also an equally-ardent white supremacist and a supporter of slavery.

He was responsible for the current seal of Tennessee.

He published the Knoxville Whig, an anti-secession pro-Union Whig newspaper in Knoxville, TN.