Lesbonax of Mytilene was a Greek grammarian and rhetorician from Mytilene on Lesbos, active during the 1st century CE in the early Roman Imperial period. Beyond this professional designation and origin, no specific biographical details are recorded.

His primary surviving work is the grammatical treatise On Figures, which may be incomplete. This is his only securely attested title, though some sources mention other rhetorical works. Lesbonax contributed to the technical study of rhetorical and grammatical figures. His work On Figures was cited by later grammarians like Herodian and Apollonius Dyscolus, establishing it as a reference within its specialized scholarly tradition. His historical impact is that of a specialist within the grammatical and rhetorical disciplines of the early Roman Empire.