August Mau (15 October 1840 – 6 March 1909) was a German art historian and archaeologist who worked with the Deutsches Archäologisches Institut while studying and classifying the Roman paintings at Pompeii, which was destroyed with the town of Herculaneum by volcanic eruption in 79 AD. The paintings were in remarkably good condition due to the preservation by the volcanic ash that covered the city. Mau first divided these paintings into the four Pompeian Styles still used as a classification.

Mau was born in Kiel, where he read Classical Philology at the University of Kiel, and then at the University of Bonn. He moved to Rome, for reasons of ill-health, in 1872, where he became Secretary to the German Archaeological Institute and catalogued the holdings of its extensive library. His interests lay above all in Pompeii, with inscriptions and Roman wall paintings, where he built upon the earlier work published by Wolfgang Helbig and Giuseppe Fiorelli.

Mau died in Rome in 1909.