William Bernard Haeffner (July 18, 1894 – January 27, 1982) was an American Major League Baseball catcher.

He played for the Philadelphia Athletics during the 1915 season, the Pittsburgh Pirates during the 1920 season, and the New York Giants during the 1928 season.

Haeffner served as the head baseball coach as La Salle University from 1947 to 1952.

He died on January 27, 1982, and is interred at Mount Peace Cemetery in Philadelphia, Pennsylvania.

[1] This biographical article relating to an American baseball catcher born in the 1890s is a stub.