Elmer Joseph "Doc" Hamann (December 21, 1900 – January 11, 1973) was a Major League Baseball player. He only appeared in one game, a 15–5 loss to the Boston Red Sox while pitching for the Cleveland Indians on September 21, 1922. Hamann co-holds a dubious record which can never be broken; since Hamann faced seven hitters and did not record a single out, he retired with a lifetime Earned Run Average of infinity.