Johan August Arfwedson (January 12, 1792 - October 28, 1841), Swedish chemist and the discoverer of lithium (1817).

Arfwedson belonged to a wealthy bourgeois family, the son of the wholesale merchant and factory owner Jacob Arfwedson and his spouse Anna Elisabeth Holtermann. He matriculated as a student at the University of Uppsala in 1803 (at the time, matriculating at a young age was common for aristocratic and wealthy students), completed a degree in Law in 1809 and a second degree in mineralogy in 1812. In the latter year, he received an (unpaid) position in the Royal Board of Mines, where he had advanced to the position of notary (still without a salary) in 1814.

In Stockholm, Arfwedson knew the chemist Jöns Jakob Berzelius and received access to his private laboratory, where he made the discovery of the element lithium in 1817, during analysis of the mineral petalite. In 1818-1819, he made a European journey, partly in the society of Berzelius. After coming home he built his own laboratory on his estate. Arfwedson spent the larger part of his remaining life administering and multiplying his inherited wealth.

The rare mineral arfvedsonite was named after him.