The complete genome sequence of a novel comovirus identified in Guanajuato, Mexico, in a common bean plant (Phaseolus vulgaris L.) coinfected with Phaseolus vulgaris alphaendornavirus 1 (PvEV-1) and Phaseolus vulgaris alphaendornavirus 2 (PvEV-2) is presented. According to the current ICTV taxonomic criteria, this comovirus corresponds to a new species, and the name "Phaseolus vulgaris severe mosaic virus" (PvSMV) is proposed for this virus based on the observed symptoms of "severe mosaic" syndrome caused by comoviruses in common bean. PvSMV is closely related to bean pod mosaic virus (BPMV), and its genome consists of two polyadenylated RNAs. RNA-1 (GenBank accession number MN837498) is 5969 nucleotides (nt) long and encodes a single polyprotein of 1856 amino acids (aa), with an estimated molecular weight (MW) of 210 kDa, that contains putative proteins responsible for viral replication and proteolytic processing. RNA-2 (GenBank accession number MN837499) is 3762 nt long and encodes a single polyprotein of 1024 aa, with an estimated MW of 114 kDa, that contains putative movement and coat proteins. Cleavage sites were predicted based on similarities in size and homology to aa sequences of other comoviruses available in the GenBank database. Symptoms associated with PvSMV include mosaic, local necrotic lesions, and apical necrosis. This is the first report of a comovirus infecting common bean in Mexico.