OOI or Ooi may refer to:
*
Ocean Observatories Initiative, a National Science Foundation Division of Ocean Sciences program
*
Huang (surname), a Chinese surname
*
Oosterhoff type I
A globular cluster is a spheroidal conglomeration of stars. wikt:globular, Globular clusters are bound together by gravity, with a higher concentration of stars towards their centers. They can contain anywhere from tens of thousands to many mil ...
(OoI), a category of
globular clusters
* In Japanese,
Åi is sometimes written as ooi
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