Augustus Matthiessen, FRS (2 January 1831 in London – 6 October 1870 in 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.
His work in this period included the isolation of calcium and strontium in their pure states.
Matthiessen committed suicide in 1870 under "severe nervous strain" and died at St Bartholomew's Hospital in the City of London.
He left an estate valued at under £7,000, and his brother William Edward Matthiessen was his executor.
In 1997, Rudolf de Bruyn Ouboter briefly mentioned Matthiessen's 1864 paper in a figure inside his article about Heike Kamerlingh Onnes's discovery of superconductivity (Scientific American, March 1997).