Index - O
| Oersted | |
| 1 (Type/Class) | Data.Units.US.Misc |
| 2 (Data Constructor) | Data.Units.US.Misc |
| Ohm | |
| 1 (Type/Class) | Data.Units.SI, Data.Metrology.SI.Poly, Data.Metrology.SI.Mono, Data.Metrology.SI |
| 2 (Data Constructor) | Data.Units.SI, Data.Metrology.SI.Poly, Data.Metrology.SI.Mono, Data.Metrology.SI |
| OilBarrel | |
| 1 (Type/Class) | Data.Units.US.Liquid |
| 2 (Data Constructor) | Data.Units.US.Liquid |
| otherLiquidMeasures | Data.Units.US.Liquid |
| otherMassMeasures | Data.Units.US.Avoirdupois |
| Ounce | |
| 1 (Type/Class) | Data.Units.US.Avoirdupois, Data.Units.US |
| 2 (Data Constructor) | Data.Units.US.Avoirdupois, Data.Units.US |
| 3 (Type/Class) | Data.Units.US.Troy, Data.Units.US.Apothecaries |
| 4 (Data Constructor) | Data.Units.US.Troy, Data.Units.US.Apothecaries |