We present a genome assembly from an individual malePheosia gnoma(the Lesser Swallow Prominent; Arthropoda; Insecta; Lepidoptera; Notodontidae). The genome sequence is 271.3 megabases in span. Most of the assembly is scaffolded into 31 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 17.0 kilobases in length. Gene annotation of this assembly on Ensembl identified 11,628 protein coding genes.