A complete genome is presented for Methylocystis parvus OBBP, a Gram-negative aerobic methanotroph of the phylum Alphaproteobacteria. M. parvus OBBP is the genus type strain and of interest in the production of polyhydroxybutyrate and environmental microbiology. The genome consists of two plasmids (248 kbp and 205 kbp) and a chromosome (4.076 Mbp).