Ljung is a surname of Swedish origin. Notable people with the surname include:
Axel Ljung (1884–1938), Swedish gymnast who competed in the 1908 Summer Olympics Carl-Åke Ljung (1934–2023), Swedish sprint canoer Eva Lisa Ljung (born 1970), Swedish pageant titleholder Greta M. Ljung (born 1941), Finnish-American statistician
Kim Ljung (born 1971), Norwegian musician Lennart Ljung (engineer) (born 1946), Swedish academic Lennart Ljung (general) (1921–1990), Swedish Army general Martin Ljung (1917–2010), Swedish comedian, actor and singer Oscar Ljung (1909–1999), Swedish film actor Ove Ljung (1918–1997), Swedish Army general Peter Ljung (speedway rider) (born 1982), Swedish motorcycle speedway rider Peter Ljung (bowler) (born 1977), Swedish ten-pin bowler Roger Ljung (born 1966), Swedish footballer Viktor Ljung (born 1991), Swedish footballer
Fictional characters Bert Ljung