Unnur Birna Vilhjálmsdóttir (born May 25, 1984 in Reykjavík, Iceland) is a former winner of the Miss Iceland pageant. She was crowned Miss World 2005 on December 10, 2005 in the Beauty Crown Theatre located in the Chinese beach city of Sanya, by the reigning beauty queen, 2004's Miss Peru Maju Mantilla.