We present a genome assembly from a specimen of Orbicella franksi (boulder star coral; Cnidaria; Anthozoa; Scleractinia; Merulinidae). The genome sequence has a total length of 496.97 megabases. Most of the assembly (95.24%) is scaffolded into 15 chromosomal pseudomolecules. The mitochondrial genome has also been assembled, with a length of 17.08 kilobases. Gene annotation of this assembly by Ensembl identified 28 996 protein-coding genes.