Robert Marion (1766 – March 22, 1811) was a U.S. Representative from South Carolina.
Born 1766 in the Berkeley District of the Province of South Carolina, Marion graduated from the University of the State of Pennsylvania (now the University of Pennsylvania), Philadelphia in 1784.
He owned and managed a plantation at Belle Isle, South Carolina.
Marion was elected as a Democratic-Republican to the Ninth, Tenth, and Eleventh Congresses and served from March 4, 1805, until his resignation on December 4, 1810.
He died on his plantation in St. Stephen's Parish, March 22, 1811.