Castaing is a surname. Notable people with the surname include:
Jean Castaing (playwright) (1723–1805), printer and playwrightEdme Castaing (1796–1823), French physician and murdererFrancis Castaing (born 1957), French bicycle racerFrançois Castaing (born 1945), French automotive executiveJean Castaing ({{Floruit|1685–1700}), French inventor and mint officialMadeleine Castaing (1894–1992), French antique dealer and interior designerLucien Castaing-Taylor (born 1966), British anthropologist and artistJacques Chastenet de Castaing (1893–1978), French journalist, historian and diplomat