- Name - OAKES
Meaning - THE OAK
- Name - OAKLEY
Meaning - FROM THE OAK MEADOW
- Name - OBADIAH
Meaning - SERVANT OF GOD
- Name - OBED
Meaning - SERVING
- Name - OBERON
Meaning - ELF RULER
- Name - OCEAN
Meaning - OCEAN
- Name - ODED
Meaning - RESTORER
- Name - ODRAN
Meaning - LITTLE SALLOW ONE
- Name - OGDEN
Meaning - FROM THE OAK VALLEY
- Name - OLAF
Meaning - RELIC
- Name - OLI
Meaning - ELF ARMY
- Name - OLIN
Meaning - HOLLY
- Name - OLIVER
Meaning - OLIVE TREE
- Name - OLIVER
Meaning - ELF ARMY
- Name - OLLIE
Meaning - ELF ARMY
- Name - OMAR
Meaning - ELOQUENT
- Name - ONAM
Meaning - VIGOROUS
- Name - ORA
Meaning - TO PRAY
- Name - ORAN
Meaning - LITTLE SALLOW ONE
- Name - ORIAN
Meaning - PRIVILEGED BIRTH
- Name - ORMAN
Meaning - SPEARMAN
- Name - ORMOND
Meaning - DESCENDANT OF RUADH
- Name - ORMONDE
Meaning - DESCENDANT OF RUADH
- Name - ORRICK
Meaning - VENERABLE OAK
- Name - ORRIN
Meaning - LITTLE SALLOW ONE
- Name - ORSON
Meaning - LIKE THE BEAR
- Name - ORSON
Meaning - SPEARMAN
- Name - ORVAL
Meaning - GOLDEN CITY
- Name - OSBERT
Meaning - GOD-BRIGHT
- Name - OSBERT
Meaning - INSPIRED
- Name - OSBORN
Meaning - DIVINE-BEAR
- Name - OSBOURNE
Meaning - DIVINE-BEAR
- Name - OSCAR
Meaning - SPEAR OF GOD
- Name - OSCAR
Meaning - GOD-SPEAR
- Name - OSGOOD
Meaning - GOTH OF THE HEAVENS
- Name - OSGOOD
Meaning - DIVINE GAUT
- Name - OSMAN
Meaning - DIVINE PROTECTION
- Name - OSMOND
Meaning - DIVINE PROTECTION
- Name - OSMOND
Meaning - GOD PROTECTOR
- Name - OSRIC
Meaning - DIVINE RULER
- Name - OSSIAN
Meaning - LITTLE DEER
- Name - OSSIE
Meaning - GOD
- Name - OSWALD
Meaning - OF GOD-LIKE POWER
- Name - OSWALD
Meaning - DIVINELY POWERFUL
- Name - OSWIN
Meaning - GOD FRIEND
- Name - OTHNIEL
Meaning - LION OF GOD
- Name - OTIS
Meaning - SON OF OTTO
- Name - OTIS
Meaning - HEARS WELL
- Name - OTNIEL
Meaning - LION OF GOD
- Name - OTTIS
Meaning - SON OF OTTO
- Name - OVERTON
Meaning - THE UPPER TOWN
- Name - OWEN
Meaning - BORN OF YEW
- Name - OWEN
Meaning - WELL-BORN
- Name - OZZIE
Meaning - GOD
- Name - OZZY
Meaning - GOD