William Alston (1757 – June 26, 1839) was a South Carolina legislator, slave owner, planter, and horse breeder.

He was a captain during the revolutionary war under Francis Marion, the famous partisan leader.

After the return of peace he married the daughter of Rebecca Motte, and became a successful planter and a large slave-owner.

His son Joseph Alston was for several years a prominent member of the South Carolina state legislature, and governor in 1812–1814.

William Alston died on 26 June 1839 in Charleston, South Carolina.