Gerhardsen is a Norwegian surname meaning 'son of Gerhard'. The given name Gerhard or Gerhart is a Germanic Masculine name commonly given in Scandinavia. Notable people with the surname include:
Carin Gerhardsen (born 1962), Swedish author of crime fiction Einar Gerhardsen (1897–1987), Norwegian politician Gerhard Meidell Gerhardsen (1848–1912), Norwegian bailiff and politician Gerhard Meidell Gerhardsen (1885–1931), Norwegian bailiff and politician Gerhard Meidell Gerhardsen (economist) (1912–1986), Norwegian economist Marte Gerhardsen (born 1972), Norwegian civil servant, politician and organizational leader Mina Gerhardsen (born 1975), Norwegian politician Rolf Gerhardsen (1902–1971), Norwegian journalist and politician Rune Gerhardsen (1946–2021), Norwegian politician Werna Gerhardsen (1912–1970), Norwegian politician