Thomas Bain (December 14, 1834 – January 18, 1915) was a Canadian parliamentarian. Bain was born in Scotland, the son of Walter Bain, and migrated to Canada with his family when he was three years old. They settled on a bush farm in Wentworth County near Hamilton, Ontario.He was elected to the County Council in the 1860s and became Warden. He was first elected to the Canadian House of Commons in the 1872 federal election as a Liberal.