British Prime Minister David Cameron was quick to pay tribute, closely followed by his foreign minister, William Hague.
Like Cameron, other public figures remembered being interviewed by the man famed for coaxing an apology for Watergate from former US President Richard Nixon.
NATO secretary general, Anders Fogh Rasmussen, commented on Frost's interviewing style.
That thought was echoed by Alastair Campbell, once former British Prime Minister Tony Blair's press secretary, with a tweet about what Blair told him about Frost.
Many journalists around the world spoke of their admiration for him - some talking about how he inspired them and many about what they had learned from him.
Friends and colleagues at Al Jazeera English, where he had worked since its launch in 2006, shared their memories.
Many people shared their favourite moments from his long and storied career:
Thousands more on Twitter, where David Frost's name was a top trending topic all day, simply said they had lost their favourite interviewer and that broadcasting would be all the poorer for it.