Mandl is a South German surname. Notable people with the surname include:
Alex J. Mandl (born 1943), Austrian-American businessmanDaniel Mandl (1891–1945), Czech civil engineer, inventor, student of anthroposophy, and Holocaust victim, father of Herbert Thomas MandlFelix Mandl (1898–?), Croatian businessman and entrepreneurFranz Mandl (1916–1988), Austrian footballerFriedrich Mandl (1900–1977), Austrian-Argentine businessmanHerbert Thomas Mandl (1926–2007), Czechoslovak-German author, son of Daniel MandlJubilee Jenna Mandl (born 1984), Austrian figure skaterJürgen Mandl (born 1965), Austrian athleteMaria Mandl (1912–1948), Austrian Nazi SS commandant of the female camp at Auschwitz concentration campPeter Mandl (born 1947), Swedish sculptorPetr Mandl (1933–2012), Czech mathematicianThomas Mandl (born 1979), Austrian footballer