Grey or gray box may refer to:
Science and technology Gray box testing, software testing Grey box model, in mathematics, statistics, and computational modelling Grey identification method, used in system identification
Botany Jojoba (Simmondsia chinensis), also known as gray box bush
Eucalyptus Grey box, many trees in the genus Eucalyptus, native to Australia, including: Eucalyptus argillacea (Kimberley grey box or northern grey box) Eucalyptus bosistoana (coast grey box or Gippsland grey box) Eucalyptus brownii (grey box) Eucalyptus hemiphloia (grey box); See Eucalyptus albens Eucalyptus largeana (grey box) Eucalyptus microcarpa (grey box, inland grey box or western grey box) Eucalyptus moluccana (grey box or coastal grey box) Eucalyptus normantonensis (grey box) Eucalyptus pilligaensis (narrow-leaved grey box, pilliga grey box) Eucalyptus quadrangulata (grey box) Eucalyptus rummeryi (grey box) Eucalyptus tectifica (grey box)