Horatio Gates Knight (March 24, 1818 – October 16, 1895) was an American politician, manufacturer and philanthropist who served as the 30th lieutenant governor of Massachusetts from 1875 to 1879.

At fourteen Knight was apprenticed into the retail establishment of Samuel Williston, whose principal business in Easthampton was the manufacture of buttons.

During the American Civil War he was tapped by Governor John Andrew as the military draft commissioner for Hampshire County.

In this role he relied on enlistments to fill the county's quotas for war duty, spending some of his fortune in the recruitment effort.

In 1874 he was nominated by the party to be its candidate for lieutenant governor, and served for terms under Democrat William Gaston and Republican Alexander H.