King Sigurd "Syr' Halfdansson of Norway
- Born: 960, Ringerike, Buskerud, Norway
- Marriage: Åsta Gudbrandsdatter about 996 in Norway
- Died: 1018, Norway at age 58
Sigurd was the last small-king in Norway, King of Opplandene. He was a man of great wealth, prudence and influence. He married Åsta, widow of Harald Grenske shortly after Harald's death and raised their son, the future St. Olav, from the time he was young boy. Sigurd is Evan and Eric's 30th great-grandfather. Syr means "pig", as in "one that digs in the soil".
Sigurd married Åsta Gudbrandsdatter, daughter of Gudbrand "Kula" Olafsson and Ulfhild, about 996 in Norway. (Åsta Gudbrandsdatter was born about 965 in Vestfold, Norway and died about 1020 in Norway.)