After serving her reign as Miss America 1959, Mobley embarked on what has been a long career in both film and television. She has been active in many charitable causes and was awarded the Outstanding Young Woman of the Year Award in 1966 by Mrs. Lyndon B. Johnson.
Mobley appeared in several movies, including two with Elvis Presley in 1965, Girl Happy and Harum Scarum; and on such television shows as Fantasy Island, Custer, Mission: Impossible and The Love Boat. She landed a recurring role on the show Falcon Crest and played Maggie McKinney/Drummond in Diff'rent Strokes during the series' final season, replacing Dixie Carter. Mobley was an occasional panelist on Match Game in the 1970s and appeared on Super Password with Collins during the 1980s. Coincidentally, Mobley once appeared as a guest star on Designing Women, which starred Dixie Carter. The former beauty queen joined her husband, Gary Collins, as co-host of the 1989 Miss America pageant.