- O'Neil
- O'Neill
- O'Olaf
-
Rhanullt b. c 1020
- O'Reilly
-
Bernard Joseph b. 7 Nov 1876, d. Jan 1935Bernard Joseph b. 17 Mar 1904, d. 18 Jul 1955Bernard Joseph Jr. b. 16 Jan 1937, d. 3 Apr 2000David Kevin Jr. b. 5 May 1942, d. 6 Jun 2022James b. 11 Feb 1894Judith A. b. 16 Aug 1935, d. Nov 2020Margaret b. c 1920
- O'Toole
-
Donncuan b. c 1030
Gillacaemphin b. c 1005, d. 1056
Gillachomhghaill b. c 980, d. 1041
Gillachomhghaill b. c 1055
More b. c 1114, d. 1191
Murcertac b. c 1089
- Oakes
-
Clyde Everett Jr. b. 20 Jun 1920Hannah b. Nov 1859, d. c 1901
- Oakley
-
Richard Alfred b. 14 Dec 1913, d. 23 Jun 1962
- Oates
-
Daisy b. 19 Aug 1891, d. 15 Aug 1961
- Oatman
-
Martha Elizabeth b. 10 Dec 1866, d. 1 Oct 1936
- Oberlin
-
George Dewey b. 7 Jun 1898, d. 28 Mar 1995Henry A. b. Jan 1861, d. 1936
- Ochse
-
Anna Katharina d. a 1817
- Ochsenbein
-
Alice Mary b. 28 Jan 1914, d. 11 Sep 2008
- ODell, Odell
-
Bernice Ella b. 11 Jan 1882, d. 20 May 1973Hattie Francis b. 4 Sep 1891, d. 29 Mar 1911Kenneth Ray b. 23 Dec 1929, d. 14 Sep 2009Marshall b. 19 Nov 1901, d. 20 Jan 1974