Adams died of a lung infection late Sunday at Cedars-Sinai Medical Center, the Los Angeles Times reported Monday. His friend and former agent Bruce Tufeld told the Times Adams had been in ill health since breaking his hip a year ago.
Adams catapulted to fame as the bumbling Agent 86 when "Get Smart" debuted on NBC in 1965. He co-starred with Barbara Feldon as Agent 99 and Edward Platt, simply known as "Chief."
"Get Smart" spawned two of the most popular catchphrases of the decade: "Sorry about that, Chief" and "Would you believe?"
NBC canceled "Get Smart" at the end of its fourth season in 1969, but it was picked up by CBS for its fifth and final season.