Lord Montagu, who founded the National Motor Museum at Beaulieu, has died aged 88 following a short illness.
A message on the Beaulieu website said: "It is with deep sadness that we announce the death of Edward, 3rd Baron Montagu of Beaulieu.
"He died peacefully at his home on 31st August, 2015, aged 88, after a short illness."
He is survived by his wife Fiona, his son and heir Ralph, daughter Mary and second son Jonathan.
The museum will remain open for visitors following his death, it said.
Lord Montagu inherited the 7,000-acre Beaulieu Estate, in the New Forest, aged just two when his father, John, died.
He opened his home to the public in 1952 and it grew to become a popular tourist attraction. By the mid-1960s, Beaulieu was attracting over half a million visitors a year.
In 1954, Lord Montagu was convicted of committing homosexual acts, which were illegal at the time, and jailed for 12 months.
Following his release, a new building for the museum was constructed and opened as Britain’s National Motor Museum in 1972 with room for at least 200 vehicles.
As well as championing the historic vehicle movement, Lord Montagu played a major role in the preservation of England’s historic houses and the development of the UK tourism industry.
James Elliott, group editor of Classic and Sports Car magazine, tweeted that his death was "an enormous loss to the world of classic cars".