Michael David Kilkenny is a former Major League Baseball pitcher. Born in Bradford, Ontario, Canada, the left-hander was signed by the Detroit Tigers as an amateur free agent before the 1964 season. He played for the Tigers, Oakland Athletics, San Diego Padres, and Cleveland Indians. Kilkenny is perhaps best known for giving up Frank Robinson's 500th home run on September 13, 1971, and also for being one of the few players in MLB history to be with four teams in the same season. The majority of his 139 appearances were as a relief pitcher; he also started 54 games. During his career, Kilkenny gave up 224 walks in just 410 innings, for a BB/9IP of 4.92, much higher than the American League average at that time. With 301 strikeouts, his K/9IP was 6.61, which was higher than the American League average. He finished his career with a total of 23 wins, 18 losses, 4 saves, 32 games finished, and an ERA of 4.43.