(1 May 1827 - 8 March 1852) was a Norwegian painter. Cappelen was best known for his melancholic, dramatic and romantic landscape compositions.
Hermann August Cappelen was born in Skien, Norway. He was the son of Diderik von Cappelen (1795-1866) and Margaret Noble Severine Henriette Løvenskiold (1796-1866). Both the Løvenskiold and Cappelen families were prominent Norwegian family of merchants, land owners, civil servants and politicians. His family were the owners of prominent iron works and various other properties. His grandfather, Diderik von Cappelen (1761-1828), was member of the Norwegian Constituent Assembly at Eidsvoll in 1814.
He grew up at Holden, a manor in Ulefoss in the Grenland district of the county of Telemark. After school graduation in Skien in 1845, he went to Christiania to take another exam at the University of Oslo. He subsequently went to Dusseldorf, where he studied with Hans Gude. Cappelen was a student at Kunstakademie Dusseldorf under Johann Wilhelm Schirmer in landscape painting class (1846-1850).