Gjertsen is a Norwegian surname. Notable people with the surname include:
Astrid Gjertsen (1928–2020), Norwegian politician Doug Gjertsen (born 1967), American swimmer Finn Gjertsen (born 1959), Norwegian artistic gymnast Joey Gjertsen (born 1982), American soccer player Lasse Gjertsen (born 1984), Norwegian animator, musician, and videographer Torgil Øwre Gjertsen (born 1992), Norwegian footballer
See also Randi Bakke-Gjertsen (1904–1984), Norwegian pair skater Mount Gjertsen, a mountain of Marie Byrd Land, Antarctica Gjertsen Promontory, a promontory of Marie Byrd Land, Antarctica