dna next to a surname below indicates it has been registered with the DNA linking service
and the researcher is keen to find bearers of the same surname to join a DNA project.
ons next to a user below means the user has registered a one-name study of a surname
with the Guild of One-Names Studies.
| Surname | Timeframe | Place | Researcher |
|---|---|---|---|
| OAKEY | any | Alvescot/Clanfield/Black Bourton | Richard King |
| OAKLEY | 1800-1900 | Cholsey | Roger Heeley |
| OAKLEY | Any | Any | Christine Norris |
| OAKLEY | mid 1800s | Brill | Brenda Zadoroznij |
| ODDINGTON | 1600-1800 | Any | Mick Cooper |
| ODLEY | 15:20 | any | Julia |
| OGBORN | 1700- | Shiplake,Binfield Heath | Martin Langley |
| OGBORN | <1900 | Any | Martin Langley |
| OGBOURN | 1700- | Shiplake,Binfield Heath | Martin Langley |
| OGBOURNE | 1700- | Shiplake,Binfield Heath | Martin Langley |
| OGBURN | 1700- | Shiplake,Binfield Heath | Martin Langley |
| OGDEN | 1994-1998 | Charlbury | Tom |
| OLDACRE | Any | Any | Colin Wills |
| OLDAKER | any | any | Alan Heard |
| OLDHAM | 1956 | Oxford | Ms V A Oldham |
| OLDHAM | 1956 | Burford | Ms V A Oldham |
| OLDS | 1700 - 1900 | Banbury, Adderbury | Doreen Olds |
| OLIVER | >1600 | AllStonesfield, Finstock, Fawler, Glympton, Spelsbury, Woodstock, All | Shane Bywaters |
| OLIVER | <1680 | Launton | Donnette Smith |
| OLIVER | <1900 | Stonesfield | Neil Thaler |
| OLLENBUTTEL | Any | Headington | Patricia Murphy |
| OLLNEY | >1066> | Southern Oxford | Nina L. Olney |
| OLNEI | >1066> | Southern Oxford | Nina L. Olney |
| OLNEY | >1066> | Southern Oxford | Nina L. Olney |
| ONG | Any | Any | Helengrace Perez-Ong |
| ONION | 1820 | Yelford | Chris Etheridge |
| ONLEY | >1066> | Southern Oxford | Nina L. Olney |
| ONSLOW | 1900's | Banbury | Sherry MacBeth Onslow |
| ORDWAY | 1760 | Deddington | Donna Lonon |
| ORGAN | Any | Cowley | Jill Muir |
| ORLEDGE | Any | Headington | Jo Britten |
| ORMEROD | 1860 -1900 | jericho | Jo Ormerod |
| ORPWOOD | >1721 | Bampton | Linda Dutton |
| ORPWOOD | Any | Any | Graham Orpwood |
| ORPWOOD | 1600 - 1700 | Bampton | M J Young |
| ORPWOOD | <1775 | Bampton | Pauline Kennedy |
| ORPWOOD | <1850 | Bampton | Margaret Forbes |
| ORSBORN | <1860 | Ambrosden, Banbury, Hook Norton, Southam, Leamington | G |
| ORSBOURN | Any | Chipping Norton | Pat Armer |
| ORTON | <1900 | Any | Paul Orton |
| OSBORN | >1700s | Chiselhampton; Stadhampton | Jemma Hayward |
| OSBORN | 1860-1908 | Any | Barbara I. Rowe |
| OSBORNE | 1860-1908 | Any | Barbara I. Rowe |
| OSBORNE | <1930 | Oxford | D Peasey |
| OSBORNE | Any | Any | Deborah Osborne Dunmall |
| OSBURN | 1860-1908 | Any | Barbara I. Rowe |
| OSMAN | 1840 | Oxford | Dave Horn |
| OSMAN | 1850 - 1900 | Ipsden | Richard Osman |
| OSMAN | >1840 | Oxford | Ian Mullan |
| OSMOND | 19C | Bicester | Gail Stevens |
| OSWICK | >1900 | Any | Roy Oswick |
| OTWAY | 1830 -1930 | Woodstock | John Bedwell |
| OVENALL | Any | Any | Gary Ovenell |
| OVENDEN | Any | Garsington, Headington, Cowley | Hilary |
| OVENDEN | All | Garsington | Martyn Payne |
| OVENDON | 1800-1900 | Garsington | James Booth |
| OVENELL | >1860 | Any | Joan Challis |
| OVENELL | Any | Any | Gary Ovenell |
| OVERALL | Any | Any | Roy Overall |
| OVERNELL | Any | Any | Gary Ovenell |
| OWEN | 1840-1860 | Barford/St. Michael | Shirley Binnersley |
| OWEN | 1500 - 1830 | Any | Raymond Byese |
| OWEN | >1780 | Chipping Norton | Dafde |
| OWEN | 1800-1900 | banbury | Heather Hudson |
| OWEN | 1750 - 1900 | Oxford Canal (South) | Barrington John Owen |
| OWEN | 1784-1849 | Any | Helen Potter |
| OWEN | 1847-1893 | Claydon | Rosemary Probert |
| OWEN | 1840 - 1900 | Claydon | Barbara M. Stokes |
| OXFORD | 1800's | Any | Joanne |
| OXFORD | 1850-1870 | Any | D. Culbert |
| OXFORD | 1500-1600 | unknown | Pam Oxford Williams |
| OXLADE | Any | Any | Margaret East |
| OXLADE | 1720 - 1890 | Hambledon | May Lanchbury |
| OXLADE | Any | Any | Susan M. Rogers |
| OYLY | >1066> | Southern Oxford | Nina L. Olney |