King conducted an estimated 50,000 interviews in his six-decade career, which included 25 years as host of the popular CNN talk show Larry King Live.
He died at Cedars-Sinai Medical Center in Los Angeles, according to Ora Media, a production company he co-founded.
Earlier this month, he was treated in hospital for Covid-19.
A statement was posted on his verified Facebook announcing his passing.
"With profound sadness, Ora Media announces the death of our co-founder, host and friend Larry King, who passed away this morning at age 87 at Cedars-Sinai Medical Center in Los Angeles," the statement said. "For 63 years and across the platforms of radio, television and digital media, Larry's many thousands of interviews, awards, and global acclaim stand as a testament to his unique and lasting talent as a broadcaster."
King rose to fame in the 1970s with his radio programme The Larry King Show, on the commercial network Mutual Broadcasting System.
He was then the host of Larry King Live on CNN, between 1985 and 2010, carrying out interviews with a host of guests.
He also wrote a column for the USA Today newspaper for over 20 years.
Most recently, King hosted another programme, Larry King Now, broadcast on Hulu and RT, Russia's state-controlled international broadcaster.