British PM David Cameron hails David Frost as a 'fearsome interviewer'
The UK Prime Minister offered his condolences to Sir David's wife Carina, adding: "Sir David was an extraordinary man - with charm, wit, talent, intelligence and warmth in equal measure. He made a huge impact on television and politics.
"The Nixon interviews were among the great broadcast moments - but there were many other brilliant interviews.
"He could be - and certainly was with me - both a friend and a fearsome interviewer."
Mr Blair fondly recalled interviews with the revered journalist and described news of his death as "very sad".
"Sir David Frost was a huge figure in broadcasting," he said.
"He had an extraordinary ability to draw out the interviewee, knew exactly where the real story lay and how to get at it, and was also a thoroughly kind and good natured man.
"Being interviewed by him was always a pleasure but also you knew that there would be multiple stories the next day arising from it. David was a great professional and a good friend. My deepest condolences to his lovely wife Carina and family. "
Former Lib Dem leader Sir Menzies Campbell hailed Sir David as a "peerless" broadcaster.
"To be interviewed by David Frost was never a chore, even when trying to defend the indefensible," he said.
"But his scrupulous and disarming politeness hid a mind like a vice. David Frost could do you over without you realising it until it was too late."
Shadow chancellor Ed Balls said: "Very sorry to hear of the sudden death of Sir David Frost - he was such a friendly man, but also a brilliantly beguiling interviewer".
Actor and comedian Stephen Fry expressed his shock on Twitter and said he last spoke to Sir David just two days ago.
"Oh heavens, David Frost dead? No!! I only spoke to him on Friday and he sounded so well. Excited about a house move, full of plans ... how sad."
Other TV personalities were quick to shower praise on the broadcaster and hail his skill.
TV personality Esther Rantzen spoke movingly about her friendship with the late television presenter.
She said: "I think fellow interviewers have always been awestruck by David Frost's capacity to illicit memorable, sometimes historically significant quotes from all the movers and shakers or our time - presidents, prime ministers, A*list celebrities - but for all of us who had the pleasure of knowing him socially, it is his kindness, generosity, loyalty and humour that we will miss so much.
"His summer party was always the best party of the year. His fund of anecdotes and his constant wit was a joy. In fact, it was always his greeting: 'a joy to meet you' and it was always a joy to meet him."
TV presenter Loyd Grossman described the "irreplaceable" journalist as a "master of current events", adding: "I can't think of any other broadcaster that can step into those very, very big shoes."
"He was almost the most variously talented journalist in British broadcasting history," he told Sky News.
"We have all grown up with him and lived with him. His loss will be immense to all of us. I have to say he was also an incredibly generous broadcaster to work with.
"I started working with him thirty years ago, in 1983, when I was completely inexperienced. He was always so helpful and kind and encouraging to me and to many others."
BBC producer Barney Jones, who edited Breakfast with Frost for more than 10 years, told BBC News: "He brought an enthusiasm to everything he did which was quite extraordinary.
"David loved broadcasting, did it brilliantly for more than 50 years and was eagerly looking forward to a host of projects - including interviewing the Prime Minister next week - before his sudden and tragic death.
"We will all miss him enormously."
Peter Fincham, director of television at ITV, said: "David Frost was one of the giants of television. He co-founded London Weekend Television and was a hugely influential figure in the development of ITV.
"He was a major presence on screen for five decades, able to switch effortlessly from light entertainment to interviewing world leaders. And he was the most courteous and generous man you could hope to meet, always making it seem that it was his great good fortune to know you, rather than vice versa.
"He was the epitome of old school charm."
Andrew Lloyd Webber tweeted: "Farewell David, dearest friend. ALW."
Sir Victor Blank, chairman of the female health charity Wellbeing of Women, said: "It's a sad day and David's tremendous contribution over the last half century to television will be honoured.
"David was also a marvellous husband, father and friend, but not often recognised is the time, generosity and support he gave to so many charities, not least the 25 years he has spent helping Wellbeing of Women."
BBC Director-General Tony Hall said: "You couldn't write the history of broadcasting today without realising the huge influence David had on it.
"From satire to comedy to the big political interviews, for more than 50 years he brought us the history of the world we live in today, that's the mark of the man.
"I had lunch with him just three weeks ago to discuss a new series on his work. As a broadcaster and as a friend he was always warm, enthusiastic and brilliant.
"David was one of the BBC greats and he will be hugely missed."
Alan Yentob, BBC Creative Director, added: "David Frost was not only a great broadcaster, who made an indelible mark on the history of television, he was also a wonderful man, warm hearted, generous, an exceptional friend and devoted husband to Carina and father to their boys.
"We will all miss him terribly."
Danny Cohen, director of BBC Television, also paid tribute to a "titan of broadcasting".
"He played a key role in shaping the world of television as we now know it," he said
"From 'That Was The Week That Was' through the Nixon interviews and beyond, David Frost led with razor-sharp intellect and an instinct for the biggest of stories."
Peter Jay, the founder of the TV-am franchise Sir David worked for and owned shares in, described him as an entrepreneur with a "genius for putting people together to work for a purpose" and an "extraordinary concern for detail".
Mr Jay told BBC News: "On the screen he was a very talented and original performer, but it was his talent off-screen, his quality as a human being, his capacity for friendship and loyalty, that were in my opinion the thing that raised him to quite an exceptional level."
Bob Zelnick, who worked with Sir David as executive editor on the Nixon interviews, hailed the "utterly brilliant and riveting performance" he had delivered while asking the former president about the Watergate scandal.
"Every one of us involved in that project knew that we could not survive with our reputations anywhere near intact if the perception was that Nixon had successfully countered us," Mr Zelnick told BBC News.
"The fact that it drew almost universal praise was a tribute to David's hard work and his very, very tough attitude once the bell rang and the fight started."
Satirist Rory Bremner said: "He was made for television and he made television.
"He absolutely grasped the medium and in some ways he himself almost felt that he really wasn't actually alive unless he was broadcasting.
"It ran in his blood and he achieved so many things, and was also a great family man as well. Carina and his three sons were so proud of him and there was a lot of love there."
Mr Bremner also praised Sir David's "remarkable confidence" and work ethic.
"At the height of when he was working in the 1960s I think he was doing Frost on Friday, Frost on Saturday, Frost on Sunday in Britain," he said
"Then he would get on Concorde, fly across the Atlantic and do three or four shows back to back, and then back to Britain.
"He did that for years, so much so that they recognised him on Concorde."
Foreign Secretary William Hague said Sir David was a "great broadcaster" who was "always keen to have a chat behind the scenes".
"He was a formidable interviewer," he told BBC Radio 4's World at One.
"He was also a great friend to many of us in politics."