| Name | Type | Language | Counties |
|---|---|---|---|
| Katherine Elaine Olinger | Master | English | All |
| Yamel Olivas Solis | Standardized | Spanish | Clackamas, Multnomah, Washington, Yamhill |
| ELIZABETH ANN OLSON | Standardized | ||
| Laura Ann Olson | Master | English | Clackamas, Marion, Multnomah, Polk, Yamhill |
| Kim (Kiki) Omoto | Master | English | Benton |
| CHRISTINA SUZANNE ONEILL | Master | English | All |
| LISSET ONEILL | Master | English, Spanish | Multnomah |
| Nancy L Orem | Master | English | All |
| RAUL DAVID OROZCO FUENTES | Master | English, Spanish | Benton, Linn, Marion, Polk |
| Kay Guadalupe Ortega | Standardized | English, Spanish | Jackson, Jefferson, Josephine, Klamath |