Pétur Hafliði Marteinsson (born 14 July 1973) is a retired Icelandic football player. He played for Hammarby IF in Sweden, Stabæk in Norway and Stoke City in England during his professional career. Marteinsson was capped 36 times and scored one goal while playing for Iceland. He is the son of former Icelandic international player Marteinn Geirsson.