Joseph Frederick Hassler (April 7, 1905 – September 4, 1971) was an American professional baseball shortstop.

He played in Major League Baseball (MLB) for the Philadelphia Athletics and St. Louis Browns.

Hassler was a pitcher as a schoolboy and only began playing the infield when he joined a semi-pro team in his native Fort Smith, Arkansas in 1923.

He was playing for a minor league team in Blytheville, Arkansas in 1926 when the league folded and he was picked up by the Athletics, who farmed him out to minor league teams for the remainder of that year and the following year.

This biographical article relating to an American baseball shortstop is a stub.