William B. Martin (March 17, 1846 – June 11, 1916) was an American businessman and politician.
He tried to enlisted in the 4th Vermont Infantry during the American Civil War and was rejected because he was sixteen years old.
He open a real estate and loan business in Greenfield.
From 1894 to 1898, Marti served in the Iowa House of Representatives.
Martin died at his home in Des Moines, Iowa.