Brynjolfur Andersen Willumsson (born Brynjolfur Darri Willumsson; 12 August 2000) is an Icelandic football striker who plays for Kristiansund BK.
Coming through the youth ranks of Breiðablik, he played three seasons for the senior team and was a prolific Icelandic youth international. Internationally, he was a squad member for the 2021 UEFA European Under-21 Championship.
After being scouted by one Kenneth Leren, he was signed by Norwegian side Kristiansund BK in March 2021. He made his Eliteserien debut in May 2021 against Molde.