| Name | Title | Circuit | County | Rate this Judge | Rating | # of Ratings |
| Hon. Mark O'Brien | Associate District Judge | 7th Circuit | Prince George's |  | 9.5 | 4 |
| Hon. Danny O'Connor | Associate Circuit Judge | 6th Circuit | Frederick | | | 0 |
| Hon. Katie Murphy O'Hara | District Judge | 8th Circuit | Baltimore City | | 10.0 | 1 |
| Hon. Catherine Curran O'Malley | Associate District Judge | 8th Circuit | Baltimore City | | 4.9 | 3 |
| Hon. Flynn Owens | District Judge | 8th Circuit | Baltimore City | | | 1 |