He was first married to Mary Grey[5] (1491- 22 February 1538) prior to his father's death in May 1501, and was pardoned on 15 December 1503 for having married in his father's lifetime and when under marriageable age. She was a daughter of Thomas Grey, 1st Marquess of Dorset and his second wife Cecily Bonville, Baroness Harington and Bonville. Cecily Bonville was the daughter and heiress of William Bonville, 6th Baron Harington by his wife Katherine Neville. Her maternal grandparents were Alice Montagu, 5th Countess of Salisbury and her consort Richard Neville, 5th Earl of Salisbury (jure uxoris). By Mary Grey he had three children:
Sir Richard Devereux (d. 13 October 1547). Married Dorothea Hastings. She was a daughter of George Hastings, 1st Earl of Huntingdon and Anne Stafford. They were parents to Walter Devereux, 1st Earl of Essex.[5]
Sir William Devereux of Mirevale Abbey. Married Jane Scudamore, daughter of John Scudamore. The marriage produced two daughters, Barbara Devereux and Margaret Devereux.[5]
Henry Devereux, died unmarried.[5]