John Richard Flinn (born September 2, 1954) is an American former professional baseball pitcher. Flinn pitched in all or part of four seasons between and . He had two separate stints with the Baltimore Orioles, the first in 1978-, and the second in 1982, in between which he pitched for the Milwaukee Brewers in . He had been traded from the Orioles to the Brewers for Lenn Sakata on December 6, 1979.
Jim Palmer recalled that "Flinn was a terrific pitcher with Rochester in Triple A. He had a good curve, good control, nice, sinking fastball," though Palmer noted that this was only "When he was relaxed."