Gadsby is a surname. Notable people with the surname include:
Bill Gadsby (1927–2016), Canadian professional ice hockey player Ernie Gadsby (1884–1963), English footballer Hannah Gadsby (born 1978), Australian actor and comedian Henry Gadsby (1842–1907), English composer and organist Jon Gadsby (born 1953), New Zealand television comedian and writer Matt Gadsby (1979–2006), English footballer Mick Gadsby (born 1947), English footballer Nyan Gadsby-Dolly, Trinidad and Tobago politician Walter Gadsby (born 1872), English footballer Walter Gadsby (1882–1961), English footballer William Gadsby (1773–1844), English hymn writer and Baptist pastor