William Hugh Smith (April 26, 1826 – January 1, 1899) was an American planter and politician, the 21st Governor of the U.S. state of Alabama.

From 1855 to 1859, Smith served in the Alabama House of Representatives as a "states' rights" Democrat, but he evolved into a strong Unionist.

In 1862, he escaped to the Northern United States and spent the rest of the war recruiting soldiers for the 1st Alabama Union Cavalry Regiment.

Although he had been elected in February 1868, Smith would not voluntarily take office due to voters failing to ratify the 1868 constitution.

He took only light action against the Ku Klux Klan, arguing that local law enforcement could effectively handle the situation.