- Father: Steinthor JONSSON
- Birth: ABT 1420, Thvera, , Skagafjardar, Iceland
- Death: 1502
Ancestors of Sigmundur STEINTHORSSON
/-Jon KETILSSON
/-Steinthor JONSSON
| \-Gudrun SIGMUNDSDOTTIR
Sigmundur STEINTHORSSON
Descendants of Sigmundur STEINTHORSSON
1 Sigmundur STEINTHORSSON
=Solveig THORLEIFSDOTTIR Marriage: ABT 1446, Maelifell, Skagafjardar, Iceland
2 Jon SIGMUNDSSON
=Bjorg THORVALDSDOTTIR Marriage: ABT 1497, Iceland
3 Helga JONSDOTTIR
=Thorlakur HALLGRIMSSON Marriage: 08 SEP 1555
4 Gudbrandur THORLAKSSON
=Gudrun GISLADOTTIR
4 Thordur THORLAKSSON
=Holmfridur JONSDOTTIR