Gamage is a Sinhalese or Welsh surname. Notable people with the surname include:
Anoma Gamage, Sri Lankan politicianBarbara Sidney, Countess of Leicester (1563–1621), Welsh heiressChamila Gamage (born 1979), Sri Lankan cricketerDharshana Gamage (born 1979), Sri Lankan cricketerHarry Gamage (1900–1994), American football coachJanak Gamage (born 1964), Sri Lankan cricketerK. A. Gamage (died 2009), Sri Lankan army officerLal Dharmapriya Gamage, Sri Lankan architect and politicianLalith Gamage, Sri Lankan academicPiyasena Gamage (born 1949), Sri Lankan politicianSaheli Rochana Gamage (born 1988), Sri Lankan singer