1881 Census households from Margaret O'Donnell to Elizabeth O'Neall
- Margaret O'Donnell to Michael O'Donnell
- Michael O'Donnell to Patrick O'Donnell
- Patrick O'Donnell to Thomas O'Donnell
- Thomas O'Donnell to Joseph O'Donoghue
- Joseph O'Donoghue to Mary O'Dorral
- Patrick O'Dougharty to Bernard O'Farrell
- Betsy O'Farrell to Frances O'Flaherty
- Francis O'Flaherty to Jane O'Garra
- Michael O'Garra to James O'Grady
- James Henry O'Grady to Arthur O'Hagan
- Bernard O'Hagan to James O'Hair
- James O'Hair to Michael O'Halloran
- Patrick O'Halloran to Alex O'Hara
- Alexander O'Hara to Charles O'Hara
- Charles O'Hara to Felix O'Hara
- Francis O'Hara to James O'Hara
- James O'Hara to John O'Hara
- John O'Hara to Joseph O'Hara
- Joseph O'Hara to Michael O'Hara
- Michael O'Hara to Patrick O'Hara
- Peter O'Hara to Thomas O'Hara
- Thomas O'Hara to Anne O'Hare
- Arthur O'Hare to James O'Hare
- James O'Hare to Margaret O'Hare
- Margaret O'Hare to Thomas O'Hare
- Thomas O'Hare to Mark O'Harra
- Martin O'Harra to Daniel O'Hearn
- Daniel A O'Hearn to Michael O'Kane
- Patrick O'Kane to Margaret O'Keefe
- Martin O'Keefe to Patrick O'Keeffe
- Patrick O'Keeffe to Arthur O'Leary
- Arthur O'Leary to Jeremiah O'Leary
- Jeremiah O'Leary to Michael O'Leary
- Michael O'Leary to Joseph O'Loughlin
- Patrick O'Loughlin to John O'Malley
- John O'Malley to Maurice O'Mally
- Michael O'Mally to Thomas S O'May
- William O'May to Julia O'Murney
- Elizabeth O'Nail to John O'Neal
- Margaret O'Neal to Elizabeth O'Neall