Feldon starred as Agent 99 in five seasons of the original "Get Smart" from 1965 through 1970, and returned to play the character in the 1989 made-for-television movie "Get Smart, Again" (1989) and finally in a supporting role in a short-lived revival of the series in 1995, 30 years after originating the character.
Although Agent 99 was the role that has come to define her career, Feldon was an accomplished comedienne who appeared in a wide variety of television and cinematic romps. She retired from acting in 2006.