Ngaio, a Māori word, may refer to:
- Ngaio (tree) (Myoporum laetum), also known as the mousehole tree
- Ngaio weevil (Anagotus stephenensis)
- Ngaio, New Zealand, a suburb of Wellington, New Zealand
- Ngaio railway station
- Ngaio Bealum, American comedian, musician, writer, actor, activist, and publisher
- Ngaio Beausoleil, New Zealand animal welfare researcher
- Ngaio Marsh (1895–1982), author and theatre director
- Ngaio Marsh Awards
- Ngaio Marsh House
- Ngaio Marsh Theatre
- Ngaio Marsh Theatre (TV series)