William Edgar Hahn (August 27, 1875 – November 29, 1941) was an outfielder in Major League Baseball from 1905 to 1910.

Hahn, who was born in Nevada, Ohio, started his professional baseball career at the age of 27 in the Cotton States League.

"[4] The White Sox won the pennant and faced the heavily favored Chicago Cubs in the 1906 World Series.

He finished in the league's top five in runs (87) scored, walks (84), and hits by pitches (12), while batting .255.

[2] After his baseball days were over, he became a night watchman for a cement company plant in Des Moines, Iowa.