| No. | Name | Type | Language | Counties |
|---|---|---|---|---|
| 0 | WHITNEY OCONNELL | Community | English | All |
| 22 | Soobin David Oh | Master | English | All |
| 117 | Heather Rae OLeary | Master | English | All |
| 1 | Katherine Elaine Olinger | Master | English | All |
| 0 | Yamel Olivas Solis | Standardized | Spanish | Clackamas, Multnomah, Washington, Yamhill |
| 18 | Kim (Kiki) Omoto | Master | English | Benton |
| 1 | Nancy Louise Orem | Master | English | All |
| 1 | RAUL DAVID OROZCO FUENTES | Master | English, Spanish | Benton, Linn, Marion, Polk |
| 0 | Kay Guadalupe Ortega | Standardized | English, Spanish | Jackson, Jefferson, Josephine, Klamath, Malheur, Marion, Multnomah, Polk |
| 0 | ELENA ESMERALDA ORTIZ-ROBLES | Community | Spanish | Hood River, Multnomah, Wasco |