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| Name | Pos | Team | Age | DOB | POB | Nationality | Bats | Throws | Height | Weight | Salary |
| O'Learie, Craig | 1B | Free Agent | 29 | 07/31/1989 | Oxon Hill-Glassmanor | USA | Right | Right | 6' 3" | 212 lbs | - |
| Oliver, Matt | 2B | Moose Jaw Ghostbusters | 23 | 04/24/1995 | Montreal | CAN | Right | Right | 6' 0" | 165 lbs | - |
| Ondahl, Henrik | MR | Free Agent | 32 | 08/12/1986 | Malmö | SWE | Left | Left | 6' 1" | 221 lbs | - |
| Ontiveros, Cristo | LF | Moose Jaw Ghostbusters | 24 | 10/03/1994 | Hato Mayor | DOM | Switch | Right | 5' 9" | 180 lbs | - |
| Ontiveros, Jesús | 1B | San Diego Smashers | 29 | 12/08/1989 | Bayamón | PUR | Right | Right | 6' 0" | 193 lbs | - |
| Ordóńez, José | LF | Culver City Extras | 24 | 01/23/1994 | Machiques | VEN | Left | Left | 6' 3" | 165 lbs | - |
| Ortega, Juan | MR | San Diego Smashers | 25 | 01/27/1993 | New York | USA | Right | Right | 6' 0" | 211 lbs | - |
| Ortíz, Rodrigo | 2B | Oakland Giants | 23 | 10/02/1995 | San Lorenzo | PUR | Right | Right | 6' 1" | 190 lbs | - |
| Ortíz, Tony | LF | La Crosse Loggers | 24 | 02/10/1994 | The Bronx | USA | Left | Left | 5' 10" | 175 lbs | - |
| Osborn, Chris | RF | Riverside Red Bulls | 23 | 07/29/1995 | New Orleans | USA | Right | Right | 6' 5" | 205 lbs | - |
| Ospira, Carlos | SS | Menlo Maniacs | 21 | 12/25/1997 | San Miguelito | PAN | Right | Right | 6' 2" | 195 lbs | - |
| Owens, Brad | C | Oakland Giants | 26 | 04/24/1992 | Houston | USA | Left | Right | 6' 2" | 208 lbs | - |
| Owens, George | MR | Menlo Maniacs | 24 | 04/17/1994 | Laguna Niguel | USA | Left | Left | 6' 1" | 233 lbs | - |
