Onuma, Ōnuma or Oonuma may refer to:
Onuma (surname), Japanese surname Ōnuma District, district of Fukushima Prefecture, Japan Ōnuma Station, train station in Hokkaido Prefecture, Japan Ōnuma Quasi-National Park, national park in Hokkaido Prefecture, Japan, with a famous pond also called Ōnuma
People with the given name Onuma Sittirak (born 1986), Thai volleyball player