Ora Media said in a statement on Twitter that King died aged 87 on Saturday at Cedars-Sinai Medical Centre.
Fellow broadcasters and celebrities rushed to pay tribute to the “radio and TV legend”.
NBC National political correspondent Steve Kornacki said: "Larry King was a radio and TV legend with an insatiable curiosity about people and a real sense of humor.
“He could get anyone talking, from Hollywood stars to the guy on the corner. In the 1990s, Larry King Live even became the most important show in American politics. RIP."
Christiane Amanpour, CNN’s chief international anchor, said on Twitter that King was a “master of the TV celebrity/statesman-woman interview”.
“His name is synonymous with CNN and he was vital to the network’s ascent,” said Amanpour.
“EVERYONE wanted to be on Larry King Live. May he Rest in Peace.”
Piers Morgan, who took over King’s timeslot on the channel, said: “Larry King was a hero of mine until we fell out after I replaced him at CNN & he said my show was ‘like watching your mother-in-law go over a cliff in your new Bentley.’ (He married 8 times so a mother-in-law expert)
“But he was a brilliant broadcaster & masterful TV interviewer.”
Talk show host Craig Ferguson said: “Just heard the awful news about Larry King. He taught me so much.
“He was a true mensch. He probably even taught me that word. So long pal, thanks for all the laughs. Say hi to Rickles (comedian Don Rickles who died in 2017). #RIPLarryKing.”
Just heard the awful news about Larry King. He taught me so much. He was a true mensch. He probably even taught me that word.
So long pal, thanks for all the laughs. Say hi to Rickles. #RIPLarryKing
— Craig Ferguson (@CraigyFerg) January 23, 2021
New York Governor Andrew Cuomo added: “Larry King was a Brooklyn boy who become a newsman who interviewed the newsmakers.
“He conducted over 50,000 interviews that informed Americans in a clear and plain way. New York sends condolences to his family and many friends.”
Meanwhile chat show host Andy Cohen said: “RIP Larry King!!!! I loved the easy breezy format of his CNN show, and his amazing voice.”
TV host S.E. Cupp wrote: “RIP Larry King, one of my favorite interviews and the best in the biz. So grateful I got to sit at your table.”
Comedian D.L. Hughley said: “#RIP TO AN ICON #LARRYKING. REST EASY… YOUR WORK HERE IS DONE AND YOUR LEGACY WILL LIVE ON.”