Nickname with O
- Olive
- Ozzy
- Oli
- Otto
- Ozzie
- Oliver
- Olli
- Olivia
- Opie
- Omar
- oscar
- Owen
- Oldie
- Olaf
- Osito
- Oma
- Oso
- Otter
- Omi
- Otis
- Ola
- Opa
- Ogre
- old man
- oreo
- Odie
- opal
- Ori
- Obi
- Orlando
- Oddball
- Oni
- Oppie
- Olga
- Obie
- Oppa
- Opi
- Old man
- oompa loompa
- Oliv
- Orion
- Orly
- Oppy
- Oak
- Ona
- Old fart
- Ole
- oprah
- Ovi
- Oggie
- Octo
- oggy
- Oldy
- Old lady
- Owl
- Ottie
- Omega
- Owie
- OMG
- oslo
- octopus
- Ophelia
- Oddy
- Old boy
- Oswald
- Ody
- Oddie
- Onion
- Oh baby
- Olivier
- Ossie
- Okie
- Ossi
- ossy
- Oaf
- Odin
- Obelix
- Old Sport
- Ora
- Orange man
- OLLY
- Osky
- Oscar the Grouch
- one and only
- Oct
- oger
- Osi
- oman
- Odd ball
- oops
- osvaldo
- Otty
- Oti
- oly
- Odi
- Osho
- ocean
- ong
- Oily
- Obby
The words in the list Nickname with O come from players of the word game Categories game.