Michael John Cosgrove (born February 17, 1951) is a former Major League Baseball pitcher with the Houston Astros from 1972 to 1976. Cosgrove was used primarily as a left-handed relief pitcher. His best seasons came in 1974 and 1975. In '74 he was 7-3 with a 3.50 ERA and 2 saves in 90 innings pitched. For '75 Cosgrove went 1-2 with a 3.03 ERA and recorded 5 saves in 71.1 innings pitched.