John Mercer Patton (August 10, 1797 – October 29, 1858) was a U.S. Representative from the state of Virginia.

Pattong was born in Fredericksburg, Virginia and attended Princeton College. He graduated from the medical department of the University of Pennsylvania at Philadelphia, Pennsylvania in 1818, but never practiced medicine. He studied law and was admitted to the bar and commenced practice in Fredericksburg. He was elected as a Jacksonian to the Twenty-first Congress to fill the vacancy caused by the resignation of Philip P. Barbour. Patton was reelected to the Twenty-second through Twenty-fourth Congresses and as a Democrat to the Twenty-fifth Congress, serving from November 25, 1830, to April 7, 1838, when he resigned. He was chairman, Committee on Territories in the Twenty-fourth and Twenty-fifth Congresses. After leaving Congress, he was senior councilor of Virginia and became Acting Governor of Virginia upon the resignation of Governor Thomas Walker Gilmer in 1841. After this he moved to Richmond, Virginia, and resumed the practice of law. Patton died in Richmond and is interred in Shockee Cemetery there.