Oakes, Rebel
Oaks, Trevor
Oana, Prince
Oates, Johnny (playoffs)
Obando, Sherman
Ober, Bailey (playoffs)
Oberg, Scott (playoffs)
Oberholtzer, Brett
Oberkfell, Ken (playoffs)
Obermueller, Wes
O'Berry, Mike
Obradovich, Jim
O'Brien, Bob
O'Brien, Buck (playoffs)
O'Brien, Charlie (playoffs)
O'Brien, Dan
O'Brien, Dink
O'Brien, Eddie
O'Brien, George
O'Brien, Johnny
O'Brien, Pete
O'Brien, Peter
O'Brien, Ray
O'Brien, Riley
O'Brien, Syd
O'Brien, Tommy
Ochoa, Alex (playoffs)
Ochoa, Ivan
Ock, Whitey
Ockey, Walter
O'Connell, Danny
O'Connell, Jimmy (playoffs)
O'Connell, John
O'Connor, Brian
O'Connor, Jack
O'Connor, Mike
O'Connor, Paddy
O'Day, Darren (playoffs)
O'Dea, Ken (playoffs)
O'Dea, Paul
O'Dell, Billy (playoffs)
Odenwald, Ted
Odom, Blue Moon (playoffs)
Odom, Dave
Odom, Heinie
Odom, Joseph
O'Donnell, George
O'Donnell, Harry
O'Donoghue, John
O'Donoghue, John
Odor, Rougned (playoffs)
Odorizzi, Jake (playoffs)
O'Doul, Lefty (playoffs)
Oelkers, Bryan
Oeltjen, Trent
Oertel, Chuck
Oeschger, Joe
Oester, Ron (playoffs)
O'Farrell, Bob (playoffs)
Offerman, Jose (playoffs)
Office, Rowland
O'Flaherty, Eric (playoffs)
Ogando, Alexi (playoffs)
Ogando, Cristofer
Ogando, Nefi
Ogden, Curly (playoffs)
Ogden, Jack
Ogea, Chad (playoffs)
Oglesby, Jim
Oglivie, Ben (playoffs)
O'Grady, Brian
O'Grady, Chris
Ogrodowski, Bruce
Ogrodowski, Joe
Oh, Seung Hwan (playoffs)
O'Halloran, Greg
O'Hearn, Ryan (playoffs)
Ohka, Tomo
Ohlendorf, Ross (playoffs)
Ohlman, Mike
Ohman, Will
Ohme, Kevin
O'Hoppe, Logan
Ohtani, Shohei (playoffs)
Ojala, Kirt
Ojeda, Augie (playoffs)
Ojeda, Bob (playoffs)
Ojeda, Miguel
Okajima, Hideki (playoffs)
O'Keefe, Brian
Okert, Steven (playoffs)
Okey, Chris
Okrie, Frank
Okrie, Len
Olander, Jim
Oldham, Red (playoffs)
Oldis, Bob
Oldring, Rube (playoffs)
O'Leary, Charley
O'Leary, Troy (playoffs)
Olerud, John (playoffs)
Olin, Steve
Oliva, Jared
Oliva, Jose
Oliva, Tony (playoffs)
Olivares, Ed
Olivares, Edward
Olivares, Omar
Oliver, Al (playoffs)
Oliver, Andy
Oliver, Bob
Oliver, Darren (playoffs)
Oliver, Dave
Oliver, Gene
Oliver, Joe (playoffs)
Oliver, Nate
Oliver, Tom
Olivera, Hector
Oliveras, Francisco
Oliveros, Lester
Olivo, Chi-Chi
Olivo, Diomedes
Olivo, Miguel (playoffs)
Oller, Adam
Ollom, Jim
Olmedo, Ray
Olmo, Luis (playoffs)
Olmos, Edgar
Olmsted, Al
O'Loughlin, Jack
Olsen, Barney
Olsen, Kevin
Olsen, Ole
Olsen, Scott
Olsen, Vern
Olson, Garrett
Olson, Greg (playoffs)
Olson, Gregg (playoffs)
Olson, Ivy (playoffs)
Olson, Karl
Olson, Marv
Olson, Matt (playoffs)
Olson, Reese (playoffs)
Olson, Ted
Olson, Tim
Olson, Tyler (playoffs)
Olt, Mike
Olwine, Ed
O'Malley, Ryan
O'Malley, Shawn
O'Malley, Tom
O'Mara, Ollie (playoffs)
Omogrosso, Brian
Ona, Jorge
Ondrusek, Logan (playoffs)
O'Neal, Randy
O'Neal, Skinny
O'Neil, John
O'Neil, Mickey
O'Neill, Emmett
O'Neill, Harry
O'Neill, Jim
O'Neill, Paul (playoffs)
O'Neill, Steve (playoffs)
O'Neill, Tyler (playoffs)
Onis, Curly
Onslow, Eddie
Onslow, Jack
Ontiveros, Steve
Ontiveros, Steve
Oquendo, Jose (playoffs)
Oquist, Mike
Oravetz, Ernie
Ordaz, Luis
Ordenana, Tony
Ordonez, Magglio (playoffs)
Ordonez, Rey (playoffs)
Orengo, Joe
Orf, Nate
Orie, Kevin
O'Riley, Don
Orlando, Paulo (playoffs)
Orme, George
Ornelas, Jonathan
Oropesa, Eddie
Orosco, Jesse (playoffs)
O'Rourke, Frank
O'Rourke, Jim
O'Rourke, Joe
O'Rourke, Ryan
Orr, Billy
Orr, Pete (playoffs)
Orrell, Joe
Orsatti, Ernie (playoffs)
Orsino, John (playoffs)
Orsulak, Joe
Ort, Kaleb
Orta, Jorge (playoffs)
Ortega, Anthony
Ortega, Bill
Ortega, Jose
Ortega, Oliver
Ortega, Phil
Ortega, Rafael (playoffs)
Ortenzio, Frank
Ortiz, Baby
Ortiz, Danny
Ortiz, David (playoffs)
Ortiz, Hector
Ortiz, Javier
Ortiz, Joe
Ortiz, Joey (playoffs)
Ortiz, Jose
Ortiz, Jose
Ortiz, Junior (playoffs)
Ortiz, Luis
Ortiz, Luis
Ortiz, Luis
Ortiz, Ramon (playoffs)
Ortiz, Roberto
Ortiz, Russ (playoffs)
Ortmeier, Daniel
Orton, John
Orvella, Chad
Orwoll, Ossie
Orze, Eric
Osborn, Bob
Osborn, Ozzie
Osborne, Bobo
Osborne, Donovan (playoffs)
Osborne, Tiny
Osborne, Wayne
Osburn, Pat
Osgood, Charlie
Osich, Josh
Osik, Keith
Osinski, Dan (playoffs)
Osoria, Franquelis
Osteen, Claude (playoffs)
Osteen, Darrell
Oster, Bill
Ostergard, Red
Ostermueller, Fritz
Osting, Jimmy
Ostrosser, Brian
Ostrowski, Joe (playoffs)
Ostrowski, Johnny
O'Sullivan, Sean
Osuna, Al
Osuna, Antonio (playoffs)
Osuna, Jose
Osuna, Roberto (playoffs)
Oswalt, Corey
Oswalt, Roy (playoffs)
Otanez, Michel
Otanez, Willis
Otero, Dan (playoffs)
Otero, Reggie
Otero, Ricky
Otis, Amos (playoffs)
Otis, Bill
O'Toole, Denny
O'Toole, Jim (playoffs)
O'Toole, Marty
Otsuka, Akinori (playoffs)
Ott, Billy
Ott, Ed (playoffs)
Ott, Mel (playoffs)
Ottavino, Adam (playoffs)
Otten, Jim
Otto, Dave
Otto, Glenn
Ouellette, Phil
Oulliber, Johnny
Outen, Chink
Outlaw, Jimmy (playoffs)
Outman, James (playoffs)
Outman, Josh
Overall, Orval
Overbay, Lyle (playoffs)
Overmire, Stubby (playoffs)
Overton, Connor
Overton, Dillon
Overy, Mike
Oviedo, Johan
Oviedo, Luis
Owchinko, Bob (playoffs)
Owen, Dave
Owen, Hunter
Owen, Larry
Owen, Marv (playoffs)
Owen, Mickey (playoffs)
Owen, Spike (playoffs)
Owens, Eric
Owens, Henry
Owens, Henry
Owens, Jack
Owens, Jayhawk (playoffs)
Owens, Jerry
Owens, Jim
Owens, Rudy
Owings, Chris
Owings, Micah (playoffs)
Ownbey, Rick
Oxspring, Chris
Oyler, Ray (playoffs)
Ozmer, Doc
Ozuna, Marcell (playoffs)
Ozuna, Pablo (playoffs)