James Fea III of Clestrain married twice, first to Ursilla Balfour of Notland, in Westray, and secondly to Jean Groat.
Ursilla Balfour was a daughter of Michael Balfour of Garth, in Westray. The marriage contract was signed at Notland on 17th June 1632. There were at least four children by this marriage:
Ursilla died before 1651, when James Fea III of Clestrain married Jean Groat, the daughter of John Groat of Elsness. John Groat was described as "Baillie of Stronsay". The bride's dowry was 1,000 merks. There appears to have been no issue of this marriage and after James' death in 1667 or 1668, Jean re-married, being on record in 1674 as the wife of John Mowat in South Ronaldsay.