| Oborny, Shirley | Executive Assistant To The City Manager | City Manager | 949-644-3001 | |
| Orozco, Oscar | Planner, Assistant | Community Development | 949-644-3219 | |
| Obrien, James | Firefighter Paramedic 112 Hour (On Or After 1-1-2016) | Fire | 949-644-3355 | |
| O'keefe, David | Lifeguard I | Fire | | |
| Otoole, Michael | Lifeguard I | Fire | | |
| O'leary, Ryan | Firefighter Paramedic 112 Hour (Before 1-1-2016) | Fire | 949-644-3104 | |
| Oseguera, Armando | Fire Engineer 112 Hour | Fire | 949-644-3104 | |
| O'rourke, Brian | Assistant Chief, Lifeguard Operations | Fire | 949-644-3045 | |
| Ortiz, Jill | Human Resources Analyst | Human Resources | 949-644-3310 | |
| Osterman, Nicole | Library Clerk I | Library - City | 949-717-3838 | |
| Oconnor, Pamela | Library Clerk I | Library - City | 949-717-3851 | |
| Ortez, Francisco | Maintenance Worker I | Public Works Municipal Operations | | |
| Ornelas, Alejandro | Maintenance Worker I | Public Works Municipal Operations | 949-718-3462 | |
| Oeding, August | Pool Swim Instructor | Recreation | | |
| Odom, Denise | Recreation Leader | Recreation | | |
| Ordiano, Omar | Recreation Coordinator | Recreation | 949-718-1993 | |
| Osadche, Zachary | Recreation Leader, Senior | Recreation | | |
| Olazo, Blanca | Senior Services Shuttle Driver | Recreation | 949-644-3244 | |
| O'sullivan, Mitchell | Utilities Specialist, Senior | Utilities | 949-718-4418 | |
| O'campo, Kevin | Utilities Crew Chief | Utilities | 949-718-3437 | |
