Courtenay married the American actress
A. J. Langer in a civil ceremony in 2004. A formal wedding later took place on 30 April 2005, in Los Angeles. With his father's death in 2015, the then Lord Courtenay succeeded to his father's
peerage and
estate, becoming the 19th Earl of Devon. Devon and Langer have two children. Devon announced that he had filed for divorce in November 2023. In February 2024, Devon filed to dismiss the couple's divorce application “without prejudice” and remains separated from Langer. In March 2026 Devon announced his engagement to Jemima Hannon of Elmwood House, Hampshire. Devon practised law with the firm of
Latham & Watkins from 2005 to 2018, starting at their Los Angeles, California office. In January 2014, he permanently relocated his family to London and transferred to his firm's London office. He and his family now reside at the family's ancestral home of
Powderham Castle in Devon, England. He owns a 3,500-acre estate. In 2025, Devon called for the House of Lords to abolish the use of the word "Lord" to describe its peers, calling the chamber itself "gendered" and "discriminatory." He lost his position with the
abolition of hereditary membership. ==Arms==