In all the world, Sønder (Sønder 
) is an extremely rare unknown gender given name. Much more prevalently, Sønder is the last name as well as the forename.
Ib, Anders, Astrid, Betina, Rasmus, Louise, Jesper, Henrik, Mikkel, Vickie, Carsten, Kirsten, Juliane, Jørgen, Nicolai, Benjamin, Kristina, Michael, Pernille, Morten, Freja, Pia, Ole, Alan, Kent, Rune, John, Finn, Martin, Minna, Stine, Brian, Laura, Linda, Joann, Julie, Ejnar, Sofie, and Charlotte