| Name | Anzahl Personen |
| O'Shea | 1 |
| Oberhänsler | 1 |
| Oberhänsli | 2 |
| Oberholzer | 4 |
| Oberli | 5 |
| Oberlin | 2 |
| Obermair | 1 |
| Oberrecht | 1 |
| Oberreiter | 1 |
| Oberson | 7 |
| Oberstag | 1 |
| Obertüfer | 1 |
| Obi | 16 |
| Obrecht | 8 |
| Obrist | 5 |
| Ochsenbein | 236 |
| Ochsner | 5 |
| Odermann | 1 |
| Odermatt | 17 |
| Oechslin | 1 |
| Oegerli | 16 |
| Oeggerli | 13 |
| Oehen | 1 |
| Oehler | 1 |
| Oertle | 1 |
| Oesch | 4 |
| Oeschi | 1 |
| Oetterli | 1 |
| Oettli | 2 |
| Ogay | 1 |
| Ogi | 6 |
| ohne Namen | 1 |
| Ohnsorg | 2 |
| Olberding | 1 |
| Olivares | 1 |
| Oliverson | 1 |
| Olivier | 2 |
| Olson | 1 |
| Omlin | 60 |
| Onofrius | 1 |
| Oplinger | 1 |
| Oppliger | 9 |
| Orelli | 1 |
| Orif | 1 |
| Orlando | 1 |
| Orlett | 2 |
| Orschel | 5 |
| Ortlieb | 1 |
| Oser | 3 |
| Oshar | 1 |
| Osmond | 5 |
| Ospelt | 1 |
| Osswald | 1 |
| Oswald | 1 |
| Ott | 6 |
| Otter | 9 |
| Ottiger | 5 |
| Ottinger | 2 |
| Otto | 2 |
| Otz | 4 |
| Otzenberger | 4 |
| Alle Namen | A Ä B C D E F G H I J K L M N O P Q R S SCH T U Ü V W Y Z |
| Alle Orte | A Ä B C D E F G H I J K L M N O Ö P Q R S T U V W Y Z |
| Alle | Ehefrauen, deren Eltern nicht angegeben sind |