Strain HTCC2170 was isolated from surface waters off the Oregon coast using dilution-to-extinction culturing. Here, we present the finished genome sequence of a marine bacterium, Maribacter sp. strain HTCC2170. Strain sp. HTCC2170 is predicted to be a facultatively aerobic chemoorganotroph that, based on genomic sequence analysis, is capable of macromolecule degradation and anaerobic respiration.