Franklin Harper Elmore (October 15, 1799 – May 29, 1850) was a United States representative and Senator from South Carolina.

Born in Laurens District, the son of John Archer Elmore, he graduated from the South Carolina College at Columbia in 1819, studied law, was admitted to the bar in 1821 and commenced practice in Walterboro.

Elmore was reelected to the 25th Congress and served from December 10, 1836, to March 4, 1839.

From 1839 to 1850, he was president of the Bank of the State of South Carolina 1839-50; he declined appointment by President James Polk as Minister to Great Britain.

Elmore was appointed as a Democrat to the U.S. Senate to fill the vacancy caused by the death of John C. Calhoun and served from April 11, 1850, until his death.