John Snyder Carlile (December 16, 1817 – October 24, 1878) was an American merchant, lawyer, slaveowner and politician, including a United States senator.

A strong supporter of the Union cause during the American Civil War, he represented the loyalist faction of Virginia, which was eventually separated into two distinct states.

He joined the new Know Nothing political movement in 1854 and represented Virginia's 11th District in the United States House for one term.

The document pronounced Virginia's Ordinance of Secession illegal because the convention at which it had been drafted had been convened by the General Assembly, not by a referendum.

In the Senate, he was uniformly in favor of a strict construction of the Constitution, opposing all measures recognizing that there existed a rebellion of states instead of individuals, and denying the right of Congress to interfere in any way with the slaves (Carlile being a slaveowner himself).