For "real world" composer, please see Richard Wagner.

Professor Wagner was one of the lecturers at a psychological conference attended by several USS Enterprise-D crewmembers in 2369.

Deanna Troi and Data visited his phylobiology seminar with about two hundred other Federation scientists. She thought the idea of the seminar was that everyone would participate; however, the seminar was dominated by Wagner's lecture, which bored the scientists to sleep. Data, however, kept a full record of Wagner's lecture in his memory record. (TNG: "Timescape")

This character was only mentioned in dialogue.