Castaing is a surname. Notable people with the surname include:
Jean Castaing (playwright) (1723–1805), printer and playwright
Edme Castaing (1796–1823), French physician and murderer
Francis Castaing (born 1957), French bicycle racer
François Castaing (born 1945), French automotive executive
Jean Castaing ({{Floruit|1685–1700}), French inventor and mint official
Madeleine Castaing (1894–1992), French antique dealer and interior designer
Lucien Castaing-Taylor (born 1966), British anthropologist and artist
Jacques Chastenet de Castaing (1893–1978), French journalist, historian and diplomat
