Lelong is a surname. Notable people with the surname include:
- Charles Lelong (1891–1970), French track and field athlete
- Jacques Lelong (1665–1721), French bibliographer
- Lucien Lelong (1889–1958), French couturier
- Pierre Lelong (1912–2011), French mathematician
- Pierre Emile Lelong (1908–1984), French painter
- Jean-Marc Lelong (1949–2004), French comics author known for his serial Carmen Cru; see Jean-Marc Lofficier