John Charles William Fitzroy, 9th Duke of Grafton (August 1–1914–August 1, 1936) was a British peer, known from 1914-30 as Lord Sudbury.
Fitzroy was the eldest son of William Fitzroy, Viscount Ipswich (himself the eldest son of the 8th Duke of Grafton and his first wife, Margaret Rose Smith) and was educated at Trinity College, Cambridge. When his father predeceased him in 1918, FitzRoy became the heir to his grandfather's titles and succeeded to them in 1930.
The duke was killed on his 22nd birthday, unmarried and childless, while competing at the 1936 Limerick Grand Prix. he lost control of his Bugatti T59 at the junction of Roxboro and Sexton Street. The rear of the car hit the pillar at the entrance of the Christian Brothers School and burst into flames. Dragged from the blazing Bugatti by a marshal, the Duke of Grafton was taken to hospital where he died later in the day. The race continued, despite cars having to take to the pavement to avoid the conflagration at the scene of the accident.
His dukedom was inherited by his cousin, Charles, but his viscountcy of Thetford and earldom and barony of Arlington fell into abeyance between his sisters, Lady Jane and Lady Mary. The viscountcy and earldom remain abeyant, but the abeyance of his barony was terminated in 1999, in favour of Lady Jane's eldest daugther, Jennifer.