A family member announced the death but would not give details on the cause or where Carson died.
Carson took over the "Tonight Show" from Jack Paar in 1962 and reigned supreme in the time slot until he retired three decades later, winning 40 Emmys during his tenure.
"I don't know of a person in comedy or television who didn't sort of grow up with Johnny Carson as a role model," ABC quoted David Letterman as saying.
Among the memorable moments on his show was when a marmoset perched on his head and an elephant lifted him off the ground with her trunk.
Born Oct. 23, 1925, in Corning, Iowa, Carson grew up in Norfolk, Neb., and started his career doing card tricks at the local Kiwanis club as "The Great Carsoni." He joined the Naval Air Corps after high school and was honorably discharged in 1946, enrolling in the University of Nebraska where he studied drama and wrote a thesis titled, "How to write comedy jokes."
His first job on television was a 15-minute show on KNXT, Los Angeles. Red Skelton saw it and hired him. His big break was as host of the game show, "Who Do You Trust," which became top-rated for ABC.
Carson was married four times and has three sons.