We present a genome assembly from a specimen of Anthopleura xanthogrammica (giant green anemone; Cnidaria; Anthozoa; Actiniaria; Actiniidae). The genome sequence has a total length of 290.04 megabases. Most of the assembly (97.36%) is scaffolded into 19 chromosomal pseudomolecules. The mitochondrial genome has also been assembled, with a length of 20.04 kilobases. Gene annotation of this assembly by Ensembl identified 25,034 protein-coding genes.