| Once Upon a Crime @ QCPAC | - |
| On-site Mammography | 12/10/2009 8:00 am - 5:00 pm |
| Open Court Pickleball | 01/28/2020 10:00 am - 12:00 pm |
| Open Court Pickleball | 02/11/2020 10:00 am - 12:00 pm |
| Open Court Pickleball | 02/25/2020 10:00 am - 12:00 pm |
| Open Court Pickleball | 03/03/2020 10:00 am - 12:00 pm |
| Open Court Pickleball | 03/10/2020 10:00 am - 12:00 pm |
| Open House for Project Ocotillo Road - Power to Recker Roads | 08/12/2014 6:00 pm - 7:00 pm |
| OPEN HOUSE - Sonoqui Wash Channelization and Riggs Road Crossing Improvement Projects | 07/19/2011 5:00 pm - 7:00 pm |
| Open House: General Plan Amendment GP09-58-Z209-60 | 02/09/2010 6:00 pm - 7:00 pm |
| Open House: Transportation Master Plan | 10/25/2016 6:00 pm - 7:30 pm |
| Optimize Your Landscape Watering - Earth Month | 04/25/2021 |
| Optimize Your Landscape Watering - Earth Month | 04/26/2022 |
| Otter Pops with a Cop | 07/22/2023 8:30 am - 10:30 am |
| Over the Hill Gang Classic Car Show | 03/28/2015 8:00 am |
| Pack a Sustainable Lunch - Earth Month | 04/19/2022 |
| Pack a Sustainable Lunch - Earth Month | 04/18/2021 |
| Painted Desert Pinto Show | - |
| Pan de Veda Fall Cultural Festival | 10/07/2017 9:00 am - 2:00 pm |
| Pan de Veda Fall Cultural Festival | 10/13/2018 9:00 am - 3:00 pm |