Calvin Barry Blocker (born 1955 in Cleveland, Ohio) is an International Master of chess.

The winner of a record 15 Ohio championships, Blocker dominated Ohio chess during the 1980s, winning the title every year from 1981 through 1989 except 1983, when he did not participate.

[1] Blocker is also the Ohio state record holder for simultaneous games, having amassed 110 wins and 6 draws in a single exhibition.

[2] Well known as a coach, he has taught several high-profile chess players, including Marc Esserman.

This biographical article relating to an American chess figure is a stub.