John Emmanuel Mahnken (June 16, 1922 – December 14, 2000) was an American professional basketball player.

He served in the United States Army from 1943 to 1945, then embarked on a professional career in the National Basketball League with the Rochester Royals.

[2] In 1946, Mahnken was signed by Red Auerbach to the Washington Capitols of the Basketball Association of America (which merged with the NBL in 1949 to become the modern NBA).

[1] He holds the NBA record for worst career field goal percentage all-time.

This biographical article relating to a United States basketball player, coach, or other figure born in the 1920s is a stub.