Nootka cypress (Cupressus nootkatensis or Xanthocyparis nootkatensis), formerly Chamaecyparis nootkatensis, is a cypress (Cupressaceae) with a chequered taxonomic history. First described as in the genus Cupressus as Cupressus nootkatensis in 1824, it was transferred to Chamaecyparis in 1841 on the basis of its foliage being in flattened sprays, as in other Chamaecyparis but unlike most (though not all) Cupressus.

However, this placement does not fit with the morphology and phenology of the cones, which are far more like Cupressus. Genetic evidence, published in Amer. J. Botany 87: 1044-1057 (2000) strongly supported its return to Cupressus.

More recently, in Novon 12: 179-189 (2002), it was transferred to a new genus Xanthocyparis, together with the newly discovered Vietnamese cypress Xanthocyparis vietnamensis; this species is remarkably similar to Nootka cypress and the treatment has many arguments in its favour, but has yet to receive universal acceptance.

Nootka cypress is an evergreen tree to 40m tall, commonly with pendulous branches. The foliage is in flat sprays. The cones have 4-6 scales, and resemble the cones of Cupressus lusitanica (another Cupressus species which can show foliage in flat sprays) fairly closely, except being somewhat smaller, typically 10-14mm diameter; each scale has a stout, pointed triangular bract about 1.5mm long, again similar to other Cupressus and unlike the crescent-shaped, non-pointed bract on the scales of Chamaecyparis.