John Gaillard (September 5, 1765 – February 26, 1826) was a U.S. Senator from South Carolina.Gaillard was born in St. Stephen's district, South Carolina, on September 5, 1765. He was of Huguenot descent. He was elected to the United States Senate in place of Pierce Butler, who resigned, and served from December 6, 1804 until his death in Washington, D.C. on February 26, 1826. During his tenure, Gaillard voted for the war of 1812.