Zenas Newton Estes Jr. (December 6, 1877 – February 23, 1943) was an American football coach. He served as the head football coach at the University of Mississippi (Ole Miss) in 1900. During his one-season tenure at Ole Miss, Estes compiled an overall record of zero wins and three losses (0–3). In 1899, he graduated from the University of Virginia in law. He later worked as an attorney Memphis, Tennessee. He died of a heart attack in 1943.