| Name | Type | Language | Counties |
|---|---|---|---|
| HENRY OBELNICKI | Master | English | Clatsop, Columbia, Hood River, Lincoln, Multnomah, Washington |
| EZELMA ANN OBUHORO | Master | English | Multnomah, Washington |
| RUTH (Noemí) NOEMI OCHOA | Master | English, Spanish | All |
| TRISTA MICHELLE OCHOA | Master | All | |
| WHITNEY OCONNELL | Community | English | All |
| CATHERINE ANN OEHLER | Master | English | Clackamas, Multnomah, Washington |
| Soobin David Oh | Master | English | All |
| HEATHER OLEARY | Master | English | All |
| Katherine Elaine Olinger | Master | English | All |
| Yamel Olivas Solis | Standardized | Spanish | Clackamas, Multnomah, Washington, Yamhill |