| Surname | Individuals |
|---|---|
|
O'Bridges
|
1 |
|
O'Brien
|
3 |
|
O'Connor
|
3 |
|
O'Neill
|
1 |
|
O'Rourke
|
1 |
|
Obdrzalek
|
3 |
|
Oberg
|
1 |
|
Ocenasvova
|
1 |
|
Odegard
|
1 |
|
Oestriecher
|
1 |
|
Okray
|
1 |
|
Oliverius
|
2 |
|
Ollenburg
|
1 |
|
Olrich
|
1 |
|
Olsen
|
4 |
|
Olsen Bugge
|
1 |
|
Olson
|
11 |
|
Olsowski
|
1 |
|
Olstead
|
1 |
|
Onsager
|
1 |
|
Opat
|
8 |
|
Opichka
|
6 |
|
Opicka
|
14 |
|
Opperman
|
10 |
|
Oppermann
|
5 |
|
Orlando
|
2 |
|
Orr
|
1 |
|
Orrison
|
1 |
|
Orth
|
3 |
|
Osborne
|
2 |
|
Osburne
|
1 |
|
Osterman
|
1 |
|
Osthoff
|
1 |
|
Ostrander
|
1 |
|
Oswald
|
1 |
|
Osweiler
|
1 |
|
Otiker
|
1 |
|
Ott
|
14 |
|
Otte
|
1 |
|
Otter
|
1 |
|
Otto
|
1 |
|
Ouska
|
1 |
|
Ouzky
|
1 |
|
Oxenham
|
1 |