A new genus, Neocupressus de Laubenfels, is erected for the New World cypresses (Cupressaceae) to separate them from Callitropsis Oersted, where they have recently been placed. This is based on several sharp morphological distinctions. A new hybrid nothogenus, ×Neocupropsis de Laubenfels, is also erected to accommodate hybrid species from various species of Neocupressus and Callitropsis. The new combinations are: Neocupressus arizonica (Greene) de Laubenfels, N. arizonica var. glabra (Sudworth) de Laubenfels, N. arizonica var. nevadensis (Abrams) de Laubenfels, N. arizonica var. montana (Wiggins) de Laubenfels, N. bakeri (Jepson) de Laubenfels, N. goveniana (Gordon) de Laubenfels, N. goveniana var. abramsiana (C. B. Wolf) de Laubenfels, N. goveniana var. pygmaea (Lemmon) de Laubenfels, N. guadalupensis (S. Watson) de Laubenfels, N. guadalupensis var. forbesii (Jepson) de Laubenfels, N. lusitanica (Miller) de Laubenfels, N. lusitanica var. lindleyi (Klotzsch in Endlicher) de Laubenfels, N. macnabiana (A. Murray bis) de Laubenfels, N. macrocarpa (Hartweg) de Laubenfels, N. sargentii (Jepson) de Laubenfels, ×Neocupropsis leylandii (A. B. Jackson & Dallimore) de Laubenfels, ×N. notabilis (A. F. Mitchell) de Laubenfels, and ×N. ovensii (A. F. Mitchell) de Laubenfels. A lectotype is selected for N. lusitanica var. lindleyi.