Randolph Sinks Foster (February 22, 1820 – May 1, 1903) was an American bishop of the Methodist Episcopal Church, elected in 1872.

Born on February 22, 1820, at Williamsburg, Ohio, U.S., the son of Israel Foster and Mary "Polly" Kain,[2] he attended Augusta College in Kentucky, but left to become a Preacher in the Ohio Conference of the Methodist Episcopal Church when he was only seventeen.

Prior to his election to the episcopacy, Foster served in pastoral appointments and in educational work.

After the death of Drew's first President in 1870, Foster was elected to that post, remaining there until becoming a bishop in 1872, when he was assigned to the Cincinnati, Ohio area.

Foster wrote the book Objections to Calvinism as it is: in a series of letters addressed to N.L.