William Orlando Butler (April 19, 1791 – August 6, 1880) was an American politician and U.S. Army major general from Kentucky. He served as a Democratic representative from Kentucky from 1839 to 1843, and was the Democratic vice-presidential nominee under Lewis Cass in 1848.

Born in Jessamine County, Kentucky, Butler studied law after graduating from Transylvania University. He served in the War of 1812, taking part in the Battle of the Thames and the Battle of New Orleans. After the war, he practiced law in Carrollton, Kentucky, and briefly served in the Kentucky House of Representatives. He served in the United States House of Representatives from 1839 to 1843 before running for Governor of Kentucky in 1844. He lost the 1844 gubernatorial election to Whig nominee William Owsley.

During the Mexican–American War, Butler served as a major general of volunteers. He was General Zachary Taylor's second-in-command during the Battle of Monterrey and later succeeded Winfield Scott as the commander of American forces occupying Mexico City. The 1848 Democratic National Convention nominated a ticket of Cass and Butler, but the Whig ticket of Taylor and Millard Fillmore won the 1848 presidential election. He attended the Peace Conference of 1861, which sought to defuse the secession crisis that arose following the 1860 presidential election. During the Civil War, Butler was a War Democrat who favored the Union.

Butler, the son of Mildred Hawkins and Gen. Percival Butler, was born in Jessamine County, Kentucky (then Fayette County), and graduated from Transylvania University in 1812. He began the study of law with Robert Wickliffe, but his education was interrupted by the War of 1812.

When the War of 1812 began, Butler volunteered as a private to fight the British and the Indians. He took part in the Battle of the River Raisin. During the battle, Butler and fellow soldiers defended themselves behind a fencerow. The Indians poured such an intense fire on the fencerow that when it was over Butler found that his clothes were riddled with bullets. While the British were being decimated by American riflemen behind the cover of fences from the left position of the American lines, the British placed their soldiers in the cover of a barn in front of the American positions 150 yards away. Butler volunteered to conduct a hit-and-run operation to destroy the barn to deprive the British of cover in the barn. Butler carried a firebrand in the face of steady enemy gunfire, Butler raced to the barn and set it ablaze. Butler withdrew back to the American lines to gather straw. He then raced to the barn to place the straw on the fire. With the barn destroyed, Butler safely returned to the American lines. Later, the whole American force were defeated and captured.

After the British captured Butler and sent him to Fort Niagara where he remained until the British freed him on parole. He returned to Kentucky only to join the American forces that met the British and Indians at the Battle of the Thames in 1813.

Butler and his men were sent to New Orleans to assist Andrew Jackson in the city's defense. He distinguished himself during the Battle of New Orleans. Among the men under his command was future Florida governor Richard Keith Call, who would remain lifelong friends with Butler.

After the end of the War of 1812, Butler returned to Kentucky, resumed his legal studies, and attained admission to the bar. From 1817 to 1844, he practiced law in Carrollton. Butler served in the Kentucky House of Representatives in 1817 and 1818. From 1839 to 1843, he served as a congressman. In 1844, he received a unanimous nomination of the Democratic Party for governor. Described as the most formidable candidate that the Democrats had ever nominated for governor, Butler's race against Whig candidate William Owsley was close. Owsley won with 59,680 votes to Butler's 55,056.