Nitrosospira briensis strain C-128 is an ammonia-oxidizing bacterium isolated from an agricultural soil environment. Nitrosospira briensis is the type species for the Nitrosospira genus. N. briensis C-128 was sequenced with PacBio RS technologies at the DOE-Joint Genome Institute Program CSP 2010. The genome contains one chromosome of 3.21 Mb and no plasmids. We identified 3,073 gene models 3,018 of which are protein coding. The gene inventory supports chemolithotrophic metabolism with indications for its soil environment. We also present for the first time an SEM of this organism as well as a new phylogenetic tree analysis.