The Coventry-born star, who was made a CBE in 1991, worked in close collaboration with playwright Samuel Beckett, who described her as a perfect actress.
She died in the early hours of Sunday at a nursing home in London, her son Matthew Muller told the BBC.
"I could not have asked for a more loving mum," he said.
"She had an incredible career - but first and foremost she was my mum - and that's who I will miss," he added.
News of her death prompted a string of tributes on Twitter, among them messages from Gary and Martin Kemp of Spandau Ballet fame.
Whitelaw appeared with them in 1990 film The Krays, playing Violet Kray, mother of the criminal Kray twins, to Gary's Ronnie and Martin's Reggie.
"Deeply saddened that Billie Whitelaw has died," tweeted Gary Kemp. "I'll always remember her as a generous and towering actor, and 'Mum'."
His sentiments were echoed by his brother Martin, who tweeted: ""Desperately sad to hear the news... an honour to get to know you on The Krays."Born in 1932, Whitelaw made her radio acting debut aged just 11 and made her first stage appearance in Bradford in 1950.
She was well known for her role as Mrs Baylock in horror film The Omen and more recently appeared in the comedy Hot Fuzz.
That film's director Edgar Wright tweeted that he was "very sad to hear that the magnificent Billie Whitelaw passed away" while adding he was "so very happy" to have worked with her.
Hot Fuzz was her last feature film and in a long tribute on his website Wright wrote that filming with her was an honour.
"She made me laugh a lot. She had a wicked sense of humour and could be devastatingly funny."
He admitted to frequently questioning her about her illustrious career and said "she was both very proud of her career and sometimes amusingly dismissive".
Whitelaw won two Baftas, in 1969 and 1973, and appeared in a number of TV series, including BBC One's Dixon of Dock Green.
In her autobiography Billie Whitelaw... Who He?, however, she acknowledged it was her work with Beckett that generated the most interest.
Without their association, she wrote, "nobody would have been remotely interested in my autobiography."
Whitelaw was married to actor Peter Vaughan between 1952 and 1966. She later married German actor and writer Robert Muller, who died in 1998.
Last week the University of Reading announced it had purchased Whitelaw's Samuel Beckett archive - a collection including correspondence, annotated playscripts and costumes - for £35,000.Scottish actor Douglas Henshall, US actress Mia Farrow and singer Toyah Wilcox are among others to have paid tribute to Whitelaw on Twitter.
"Thank you Billie for being a role model and an inspiration," tweeted Wilcox, while Henshall - who appeared with the actress in 1990s drama Firm Friends - remembered her as "lovely".
Mia Farrow, who played Whitelaw's Mrs Baylock role in the 2006 remake of The Omen, said she had been "magnificent" and "never less than great".
"Sad to see Billie Whitelaw has died," tweeted comedian Robin Ince. "I'd suggest a minute's silence, but I imagine Beckett would suggest it should be much longer than that."
