August Beer (31 July 1825 – 18 November 1863) was a German physicist and mathematician. Beer was born in Trier, where he studied mathematics and natural sciences. He worked for Julius Plücker in Bonn afterwards, where he earned a Ph.D. in 1848 and became a lecturer in 1850. In 1854, Beer published his book Einleitung in die höhere Optik. His findings, together with those of Johann Heinrich Lambert, make up the Beer-Lambert law. Beer became a professor of mathematics at Bonn in 1855. He died in Bonn in 1863.