Hill never owned his own home in London, and instead preferred to rent a flat rather than buy one. He rented a double-room apartment in the London district Queen's Gate for 26 years until around 1986 when he moved to Fairwater House in Teddington. While looking for somewhere to live, he stayed at 22 Westrow Gardens in Southampton. He also never owned a car, although he could drive.

Despite being a millionaire many times over, he continued with the frugal habits that he picked up from his parents, notably his father, such as buying cheap food at supermarkets, walking for miles rather than paying for a taxi unless someone picked up the tab for a limousine, and constantly patching and mending the same clothes even when the balance on his account at the Halifax Building Society reached seven figures.

Hill never married and he had no children. He had proposed to two women, but neither accepted. Shortly after his death in 1992, actress Annette Andre said that she turned down his proposal of marriage in the early 1960s. Because of his eccentricity and reclusive lifestyle, rumours circulated that he was gay, but he always laughingly denied them.

Hill was a huge Francophile and enjoyed his visits to France, notably to Marseille, where until the 1980s, he could go to outdoor cafes anonymously, travelling on public transport and socialising with local women. He spoke French fluently and also knew basic German, Spanish, Dutch, and Italian. Foreign travel was the only luxury that he permitted himself, and even then, he would stay in modest accommodations rather than five-star hotels.

Hill’s grave at Hollybrook Cemetery, Southampton
Hill's health declined in the late 1980s. After a mild heart attack on 24 February 1992, doctors told him he needed to lose weight and recommended a heart bypass. He declined, and a week later was found to have kidney failure. He died at the age of 68 on 20 April; on 22 April, after several days of unanswered telephone calls he was found dead in his armchair in front of the television. The cause of death was recorded as coronary thrombosis. Hill was buried at Hollybrook Cemetery near his birthplace in Southampton, on 26 April 1992.

Probate was granted on Hill’s estate in London on 5 June 1992, when its value at the time of his death was given as £7,548,192, equivalent to £15,735,380 in 2019.

During the night of 4 October 1992, following speculation in the media that Hill had been buried with a large amount of gold and jewellery, grave robbers excavated the grave at Hollybrook Cemetery and broke open the coffin, the open grave's condition being found by a passer-by the following morning. After a police examination of the scene, the coffin was re-closed and the grave filled back in by cemetery workers, and as a security measure, a 1-foot-thick concrete slab was placed over it.