Captain Spier Spencer (c. 1770 November 7, 1811) was an Indiana militia officer who commanded a company of mounted riflemen known as the Yellow Jackets at the Battle of Tippecanoe. Spencer County, Indiana was named in his honor. A native of Virginia, Spencer moved to Kentucky with his parents. He married Elizabeth Polk, daughter of Capt. Charles Polk, in Bardstown, Nelson County, Kentucky on January 18, 1793. Spencer and his wife moved to Vincennes, Indiana. In 1809 Spencer was appointed by Governor William Henry Harrison as the first sheriff of Harrison County, Indiana. He moved his family to Corydon and served in that office until his death.