He played thirteen seasons with eight clubs: the Chicago Orphans (1901), New York Giants (1902), Boston Beaneaters (1904–05), Cincinnati Reds (1906), St. Louis Browns (1907), Washington Senators (1907–09), Detroit Tigers (1909–12), and Brooklyn Tip-Tops (1914–15).

He was the fourth of six brothers, and all of them played professional baseball, with five of them (Jim, Ed, Frank, Joe, and Tom) appearing at the major-league level.

After his baseball career, Delahanty moved back to Cleveland occasionally playing in exhibition games with his brothers, where he lived until he died.

He was traded mid-season by the Senators to the Tigers in 1909 for Germany Schaefer and played in his only World Series that season, batting .346 with 4 RBI in 7 games against the Pittsburgh Pirates.

[3] He stayed in the major leagues until the middle of the 1912 season, having encountered illness and injuries that year that limited his productivity.