Buckingham Palace has confirmed that the Queen had been informed of his death.
Born Anthony Armstrong-Jones, he was made the Earl of Snowdon in 1961 and was given a life peerage in 1999.
He has worked with Vogue and the Sunday Times Magazine on a number of hard-hitting documentary subjects too, including loneliness and mental health.
Armstrong-Jones second wife, formerly married to film director Michael Lindsay-Hogg, became Countess Snowden.
Snowdon was admired for his discretion, never speaking with the media about the breakup of the marriage in 1978, and rejecting offers to write a book about it.
Our thoughts are with Lord Snowdon's children and the entire British Royal Family during this hard time.
His body of photographic work featured the cream of British society, although he was usually dismissive about his work.
He was born on 7 March 1930 into a family of minor gentry.
Following a short engagement, they married on May 6, 1960 at Westminster Abbey, to much public support. "It was very avant-garde".
Lord Snowdon also photographed Prince Harry as a teenager, a young Princess Royal, Diana with her sons when they were babies, the Queen Mother and numerous other royal portraits.
The Snowdon Trust, the charity that gives grants to disabled students founded by Snowdon in 1981, said its thoughts were with his family.
Image copyright Getty Images Image caption Lord Snowdon at an exhibition of his photographs circa 1975 in NY. The couple, who had one daughter, separated in 2000.