Erna Björk Sigurðardóttir (born 30 December 1982) is an Icelandic former footballer who played as a defender. She was part of Iceland's national team and competed in UEFA Women's Euro 2009. Erna captained Breiðablik. She retired after the 2009 season but her last match was with the national team against Portugal in the 2010 Algarve Cup.