We present a genome assembly from an individual male Bombus campestris (the Field Cuckoo-bee; Arthropoda; Insecta; Hymenoptera; Apidae). The genome sequence is 275 megabases in span. Most of the assembly is scaffolded into 25 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 24.7 kilobases in length. Gene annotation of this assembly on Ensembl identified 12,993 protein coding genes.