John William McGrath (March 10, 1891 – February 18, 1924) was a Canadian amateur ice hockey player and private secretary and advisor to former President of the United States Theodore Roosevelt between 1912 and 1916.

McGrath led the AAHL with 18 goals during the season but the Wanderers lost the championship title to the Brooklyn Crescents in a playoff game.

McGrath was a diminutive player, standing only 5 feet and 2 inches, but he had a rough and tumble playing style and a hard shot that helped him score many goals.

While in New York City McGrath's proficiency as a stenographer led him to a private secretarial position with former President of the United States Theodore Roosevelt.

McGrath later worked as a secretary for American politician and businessman George Walbridge Perkins, a friend of his former employer Theodore Roosevelt.