Augustus Matthiessen, FRS (2 January 1831, London – 6 October 1870, London), the son of a merchant, was a British chemist and physicist who obtained his PhD in Germany at the University of Gießen in 1852 with Johann Heinrich Buff. He then worked with Robert Bunsen at the University of Heidelberg from 1853 to 1856. His work in this period included the isolation of calcium and strontium in their pure states.