The genome sequence of a novel RNA virus was identified by analyzing transcriptome data obtained from the stem sample of a blue agave (Agave tequilana) plant. Sequence comparison and phylogenetic analysis showed that the RNA virus, Agave virus T (AgVT), was a new member of the genus Tepovirus in the family Betaflexiviridae. AgVT genome had three open reading frames: a 1605-amino acid (aa) replicase (REP), 355-aa movement protein (MP), and 220-aa coat protein (CP). Phylogenetic analyses based on the REP, MP, and CP sequences of AgVT, previously reported tepoviruses, and other Betaflexiviridae viruses revealed that tepoviruses could be classified into two subclades: "potato virus T (PVT)-clade" and "Prunus virus T (PrVT)-clade." PVT, the type species and founding member of the genus Tepovirus, belong to "PVT-clade" along with AgVT, while the other five tepoviruses belong to "PrVT-clade." The genome sequence of AgVT may be useful for studying the phylogenetic relationships between tepoviruses and other closely related viruses. Keywords: Agave virus T; Tepovirus; Betaflexiviridae; blue agave; Agave tequilana.