James Fea I of Clestrain married Margaret Groat, who was probably a daughter of Malcolm Groat of Tankerness. While the date of their marriage is not known, it was certainly not more than ten years prior to the granting of the feu of Clestrain. They had, at least, four sons:

• James Fea II of Clestrain, who succeeded to the title

• Oliver Fea in Mussiter, Stronsay. He was alive as late as 1662 and had at least two children:
  

  John Fea

  Marie Fea. It is known that her uncle, Robert Fea, bequeathed 100 merks to be paid to her on her marriage.

  An instrument of Sasine in the National Archives of Scotland makes reference to Olaw Fea in 1593

Instrument of Sasine By James Fea, elder of Clestrand, to James Fea, younger, his eldest son, of said lands of Clestrand and St Margarets Quoy under burden of 300 merks to be paid by same James Fea, younger, to Olaw Fea, second son of James Fea, elder, and the remaining children of said James Fea, elder, and Margaret Groit, his spouse. Witnesses, Hugh Gordon of Ballinlone, William Groit in Odness, James Maxwell of Marykirk in Sanday and Alexander Dunbar, servitor to Malcolm Groit in Tankerness  National Archives of Scotland GD 31/6 21 May 1593

• Robert Fea of Grindlay, which was a small property next Stove, in Sanday. Robert married Marabel Craigie, the sister of William Craigie of Papdale and Gairsay, who was one of Robert's executors, his will and testament being on record. He had three children before he died in 1634:
  

  James Fea, who succeeded him

  Magnus Fea, who married Marie Groat and

  Robert Fea

• Walter Fea, a tenant in Yornesetter, Stronsay

There is a record of a Barbara Fea who married an Edward Scollay and she may have been a daughter. There is also a reference to an Ursilla Fea, alive in 1623, who may have been another although there is no evidence to support this.

James Fea I of Clestrain died between July 1629 and 28th April 1630, when his testament was recorded.