Timothy Leo Cullen (born February 16, 1942) is an American former infielder in Major League Baseball who played for the Washington Senators (1966–67, 1968–71), Chicago White Sox (1968) and Oakland Athletics (1972).

[2] On February 13, 1968, Cullen was traded by the Washington Senators with Buster Narum and Bob Priddy to the Chicago White Sox for Ron Hansen, Dennis Higgins, and Steve Jones.

In a curious move, on August 2, 1968, Cullen was shipped back mid-season by the Chicago White Sox to the Washington Senators for Hansen, making them the only two players in Major League history to be traded for one another twice in the same season.

Like Gonzalo Márquez, Cullen was a valuable utility for the World Championship team providing support from the bench during the regular season.

Cullen serves as the vice president of special projects for the Single-A Fresno Grizzlies, a Colorado Rockies minor league affiliate team.