Ryūō (disambiguation)
Ryūō ('dragon king') is an annual Japanese professional shogi tournament and the title of its winner. It may also refer to:
- Ryūjin, the mythological sovereign of the Ryūgū-jō ("Dragon Palace")
 - Ryūō, Shiga, a town in Gamō District, Shiga Prefecture, Japan
 - Ryūō, Yamanashi, a former town in Nakakoma District, Yamanashi Prefecture, Japan
 - Ryūō Station, a railway station in Kai, Yamanashi Prefecture, Japan
 - Ryuoo Ropeway, an aerial lift in Yamanouchi, Nagano Prefecture, Japan
 - Ryūō Noboru (born 1983), Mongolian sumo wrestler