Cognomen Gyða (Gyða 
) , across the world, is an extremely rare surname. Much more frequently, Gyða is the forename as well as the last name.
Ölvisdóttir, Halldórsdóttir, Guðmundsdóttir, Gunnarsdóttir, Steinsdottir, Ágústsdóttir, Olgeirsdóttir, Einarsdóttir, Jóhannsdóttir, Bjarnadóttir, Björnsdóttir, Brynjólfsdóttir, Bergþórsdóttir, Steinsdóttir, Ólafsdóttir, Eyjólfsdóttir, Guðjónsdóttir, Bjarkadóttir, Elíasdóttir, Njálsdóttir, Jónsdóttir, Gongini, Sigurðardóttir, and Sveinbjörnsdóttir