[2] In 1831 he was recognised retrospectively as having been de jure 4th Earl of Devon, having succeeded his father in 1630.

Courtenay was the second but eldest surviving son of Sir William Courtenay (1553–1630), de jure 3rd Earl of Devon of Powderham Castle, Devon, by his first wife Elizabeth, daughter of Henry Manners, 2nd Earl of Rutland (1526–1563).

He married firstly, 7 November 1606, Mary (born 1586), widow of Nicholas Hurst of Oxton, Devon and eldest daughter of Sir William Pole (1561–1635), of Colcomb, Devon.

He married secondly, by 1628,[2] Elizabeth, daughter of Sir Edward Seymour, 2nd Baronet (c. 1580 – 1659) of Berry Pomeroy, Devon, by whom he had issue:[7] Courtenay died on 3 June and was buried on 5 June 1638 at Powderham, Devon.

His widow later married Sir Amos Meredith, 1st Baronet of Marston, Devon.