Avenarius (translated from German: Haber, Habermann) may refer to:
- Ferdinand Avenarius (1856–1923), a German poet
- Georgy Alexandrovich Avenarius (1903–1958), one of the founders of Soviet film criticism
- Johannes Avenarius, or Johann Habermann (1516–1590), a theologian
- Richard Avenarius (1843–1896), a philosopher