William R. Hoyt was a state senator in South Carolina during the Reconstruction era from 1868 until 1870. He represented Colleton County. He was from Massachusetts.
He served in the First Massachusetts Cavalry and was a mason by trade.
Hoyt worked as a builder in Walterboro, South Carolina. He was listed as a member of the South Carolina Senate in 1868. He was identified as "colored".
He was stabbed by a political rival on election day in 1870 and left South Carolina the following year.