Buono was cast to play villains of various ethnic origins on many television programs between 1960 and 1970. He was cast twice in 1960 in the western series The Rebel, starring Nick Adams, in the episodes “Blind Marriage” and “The Earl of Durango”. In 1962, he played Melanthos Moon in an episode of The Untouchables, titled “Mr. Moon”, where he played a San Francisco art and antique dealer who hijacked a supply of the paper used for printing United States currency. In a 1963 episode of the same series, titled The Gang War, he played Pamise Surigao, a liquor smuggler competing with the Chicago mob.

He played another villain in a 1967 unsold TV pilot film based on the Dick Tracy comic strip.

Buono made a guest appearance as Hannibal Day in the Get Smart episode “Moonlighting Becomes You”, originally airing January 2, 1970, and appeared three times as Dr. Blaine in the sitcom Harrigan and Son, starring Pat O’Brien and Roger Perry as a father-and-son team of lawyers. He appeared in a segment of Night Gallery titled “Satisfaction Guaranteed”. He also appeared in an episode of Hawaii Five-O, “The $100,000 Nickel”, in which he played thief Eric Damien. It first aired on December 11, 1973. He made two memorable appearances on The Odd Couple, once in the episode “The Exorcists” and again in “The Rent Strike”, where he portrayed Mr. Lovelace. In 1976, he appeared in comedy The Practice, portraying Bernard on the episode “Jules and the Bum”. He also made nine appearances on the 1977 series Man from Atlantis, appearing all nine times as Mr. Schubert, the enemy of the main character.

In the late 1970s and in 1980, Buono played the millionaire father of the memory-impaired Reverend Jim Ignatowski on Taxi. Buono died before the end of the series. One episode was made where Jim learns to cope with his father’s death.

In 1980, Buono appeared in the television movie Murder Can Hurt You as Chief Ironbottom, a parody of the title character from Ironside. His later roles were more of pompous intellectuals and shady con men, although he also played straight roles. In the miniseries Backstairs at the White House (1979), he portrayed President William Howard Taft.