Lord Henry Cavendish-Bentinck (28 May 1863 – 6 October 1931), known as Henry Cavendish-Bentinck until 1880, was a British Conservative politician.
Cavendish-Bentinck was the eldest son of Lieutenant-General Arthur Cavendish-Bentinck from his second marriage to Augusta Mary Elizabeth, 1st Baroness Bolsover. His paternal grandfather Lord William Charles Augustus Cavendish-Bentinck was the third son of William Cavendish-Bentinck, 3rd Duke of Portland, while William Cavendish-Bentinck, 6th Duke of Portland, was his elder half-brother. In 1880 he was granted the rank of a younger son of a duke on his half-brother's succession to the dukedom.
He entered Parliament for Norfolk North-West in 1886, defeating Joseph Arch, a seat he lost in 1892, when Arch reclaimed the seat. He returned to the House of Commons in 1895 when he was elected for Nottingham South, a seat he held until 1906 and again from 1910 to 1929.
Cavendish-Bentinck held a commission in the Derbyshire Imperial Yeomanry, where he gained the rank of lieutenant-colonel. He served in the Second Boer War in South Africa 1899–1900, where he was appointed to the Staff on 20 February 1900.
Cavendish-Bentinck married, in 1882, Lady Olivia Caroline Amelia, daughter of Thomas Taylour, Earl of Bective, and granddaughter of the 3rd Marquess of Headfort. She was known as Lady Henry Bentick, and was mentioned in despatches (29 November 1900) by Lord Roberts, Commander-in-Chief, for civilian services during the Second Boer War.
Lord Henry died in October 1931, aged 68. Lady Henry died in November 1939, aged 70.