Eric O’Flaherty

Brian O’Grady

Hal O’Hagan

Harry O’Hagan owns two distinctions that will never be equaled.…

Greg O’Halloran

Kid O’Hara

Tom O’Hara

Bill O’Hara

O’Keefe

Charley O’Leary

Dan O’Leary

If God had not created Hustling Dan O’Leary, Damon Runyon…

Troy O’Leary

Silk O’Loughlin

Many of the umpires of the Dead Ball Era made their mark with…

Patrick O’Loughlin

Ryan O’Malley

Tom O’Malley

Walter O’Malley

Walter Francis O'Malley, the owner who dragged baseball franchises…

Ollie O’Mara

Tom O’Meara

Thomas Edward O’Meara was known throughout his short tumultuous…

Luther O’Neal

Skinny O’Neal

Randy O’Neal

As the tall young right-hander strode to the mound that Tuesday…

Charles O’Neil

Ed O’Neil

Mickey O’Neil