The genome of Paracoccus marcusii KGP, isolated from the marine sediment collected from the coast of the Bay of Bengal, was sequenced using Oxford Nanopore sequencing technology. The assembled genome sequence consists of seven contigs and has a 4,085,678 bp circular chromosome with 1647 coding genes and a G+C content of 66.7%. Besides, the genome of P. marcusii KGP contains three copies of the rrn operon. The genes coding for the industrially relevant enzymes and secondary metabolites such as β-galactosidase, protease, amylase, β-glucosidase, ectoine, indigoidine, and carotenoid biosynthesis clusters were also identified in the genome. When the β-galactosidase extracted from P. marcusii KGP was mixed with a high concentration of lactose, galacto-oligosaccharides were produced, which revealed the transgalactosylation property of the enzyme. The genome sequence of P. marcusii KGP was found to have an average nucleotide identity value of 96.16 and a digital DNA–DNA hybridisation value of 73.90% with the genome sequence of P. marcusii CGMCC. Furthermore, by comparing the genome sequences of both strains, it was found that the size of the KGP genome was large, indicating the possibility of strain-specific genes in addition to core genes. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.