Michael O' Neile to John O'boyle - 1881 Census household returns
- Michael O' Neile
- Patrick O''keefe
- William S O'b Dowling
- Thomas J O'b. Goble
- Timothy O'b. O'feeley
- James G O'baird Hay
- Frederick O'barrman
- Michael O'bay
- Christopher O'bee
- George O'bee
- Hannah M O'bee
- Hugh Gerald O'beirne
- John O'beirne
- Martin O'beirne
- Ormsby O'beirne
- Owen O'beirne
- Thomas O'beirne
- Thomas O'beirne
- William S O'beirne
- Michael O'beiru
- John O'beisin
- Alexander O'berg
- James O'berry
- James O'berry
- Bridget O'bien
- John O'bierne
- John O'binnie
- Michael O'birne
- Patrick G J J O'bojaene ?
- William O'borne
- John O'boy
- Anthony O'boyle
- Catherine O'boyle
- Edward O'boyle
- Edward O'boyle
- Edward O'boyle
- Felix O'boyle
- James O'boyle
- John O'boyle
- John O'boyle