George Robertson Sinclair (28 October 1863 – 7 February 1917) was an English cathedral organist, who served at Truro and Hereford cathedrals. As a young man, Sinclair was destined for the Anglican priesthood, but in 1880 his father died and Sinclair needed to earn a living immediately. He became the first cathedral organist of the new diocese of Truro. He moved from Truro to become organist of Hereford Cathedral in 1889, where he remained for the rest of his life.