Ventnor () is a seaside resort and civil parish established in the Victorian era on the south-east coast of the Isle of Wight, England, eleven miles from Newport. It is situated south of St Boniface Down, and built on steep slopes leading down to the sea. The higher part is referred to as Upper Ventnor; the lower part, where most amenities are located, is known as Ventnor. Ventnor is sometimes taken to include the nearby and older settlements of St Lawrence and Bonchurch, which are covered by its town council. The population of the parish in 2016 was about 5,800.
Ventnor became extremely fashionable as both a health and holiday resort in the late 19th century, described as the 'English Mediterranean' and 'Mayfair by the Sea'. Medical advances during the early twentieth century reduced its role as a health resort and, like other British seaside resorts, its summer holiday trade suffered the changing nature of travel during the latter part of that century.