River with O
- Ohio river
- Oder
- Ottawa
- Oklahoma
- Oklahoma river
- orinoco
- Odra
- Orlando river
- Olga
- Obey river
- obed river
- Otay
- olive
- Otter Creek
- Osage
- Hirdetés
- Olympus
- Otay River
- ottawa river
- oak orchard river
- Orljava
- Ottowa
- orion
- Omaha river
- Owl
- Onyx
- Oka
- Orinoko
- Otto
- Outaouais
- Obed
- Ocoee
- Oswego
- Ovens
- ophelia
- olympia
- ozark
- oman river
- oregan river
- Okavango
- Oneida
- Oker
- One
- Ogden
- Olt
- Ottowa River
- Okanogan
- only
- Ober
- Oise
- Oil
- over
- omaha
- ore
- olan
- Okechobee
- olentangy
- owen
- Ostsee
- olivia
- oolong
- OREGON
- Obion River
- Onions
- Ouse river
- ona
- orwell
- oval river
- Olly
- omar
- osiris
- oxe
- orange county river
- Oyster
- Opera
A River with O listán szereplő szavak a Ország Város szójáték játékosaitól származnak.