Therkildsen is a predominantly Danish patronymic surname from the name Therkild. People bearing the name include:
Hans Michael Therkildsen (1850–1925), Danish painter Mogens Therkildsen (born 1940), Danish footballer Morten Therkildsen (born 1983), Danish racing cyclist Peter Therkildsen (born 1998), Danish footballer Rasmus Therkildsen (born 1991), Danish singer
See also Thorkildsen Torkelsen Torkildsen