After her parents divorced in 1950, Elizabeth lived in New York where her father had begun his successful television series "Robert Montgomery Presents", and it was here that she made her TV debut playing opposite her father in an episode entitled 'Top Secret'.
Elizabeth quickly became a prolific and hard-working television actress, making appearances on dozens of shows and participating in the summer stock company of her father's show in the years 1953, 1954 and 1956. She also earned an Emmy nomination in 1960 for her performance as a prostitute in an episode of "The Untouchables".
She made her big screen debut in 1955 in "The Court-Martial of Billy Mitchell" and although she would make two more feature films, it would be television that would make her a star.
In December 1963, Elizabeth starred in the pilot episode of Bewitched as the beautiful, good-hearted witch 'Samantha'. The first episode aired in 1964 and the show was an immediate success. By the end of the season, Bewitched was ABC's biggest hit ever and made "industry laughing stock ABC" the #1 television network in the top 50 urban markets nationwide. Bewitched was still ABC's top show at the end of the decade. Unfortunately, ABC's success demanded the show create nearly 40 episodes a year, placing a tremendous work load on the cast, writers, and crew. Near the show's end, Bewitched had to rewrite previous episodes just to keep up. By the final season, the show was burned out. ABC moved the show to Saturday night opposite All in the Family as a stop-gag measure to prevent further ratings erosion of that time slot. Bewitched held steady and the network requested 3 more years, but Elizabeth decided it was time to move on to other projects.
Miss Montgomery continued to work in television, becoming the first and foremost "TV Movie Queen" . She created a string of c TV films, including Mrs. Sundance, A Case of Rape, The Legend of Lizzie Borden., and The Awakening Land. Elizabeth worked steady in television, always garnering high ratings. Her final film Deadline for Murder was one of the highest rated movies of 1995.
She married four times, her first husband was Frederic Gallatin Cammann, a stage manager on her father's show, their marriage lasted a brief year. Next she wed actor Gig Young, they were divorced in 1963. Also the same year she wed I Love Lucy director & TV producer William Asher, who would be one of the driving forces behind "Bewitched". Together they had three children; William, Robert and Rebecca (all 3 born during the original run of Bewitched.) They were divorced in 1973 after "Bewitched" had ended. Her fourth and final husband was actor Robert Foxworth whom she married in 1993. They had been a couple since the early 1970's.
Elizabeth received the "Lucy Award" in 1995 for Innovation in Television.
In 1995, after a short bout with cancer, Elizabeth passed away in the home she shared with her family.