Gombau was the son of Ramon I Bonfill de Castellvell but his mother is unknown. The date and place of his birth have not been found.
Gombau de Castellvell
Ramon I Bonfill de Castellvell (c1045-c1075)
Guillaume I de Castellvell
Unifred Amat d'Arles (-1011)
Riquilda de Saint-Martin