Anders was born Mary Helen Anderson in Chicago in 1934, the only child of Charles, a contractor, and Helen Anderson. Anders was of German, Irish and Swedish descent. In 1949, Anders and her mother visited Los Angeles for two weeks. They decided to remain in Los Angeles permanently while Charles Anderson remained in Chicago. While she was a student at John Burroughs Middle School, Anders met former Actress Rita Leroy who encouraged her to begin a modeling career. While working as a junior model, Anders began studying acting at the Ben Bard Playhouse. It was there that a talent scout from 20th Century Fox spotted her and signed her to a film contract in 1951.

Anders made her film debut in the 1951 musical Golden Girl. For the next two years, she appeared in small and supporting roles in several 20th Century Fox films. In 1954, Fox dropped her. Later that year, Anders joined the cast of The Stu Erwin Show. She remained with the series until its cancellation in 1955. Anders was then cast in the CBS sitcom It's Always Jan, starring Janis Paige. That series canceled after one season.

On March 25, 1955, Anders married Producer John Stephens. Anders left Stephens after three and a half months due to his physical abuse. Two weeks later, she discovered she was pregnant with the couple's first child. Their daughter, Tina Beth Paige Anders, was born in March 1956. Anders and Stephens were divorced in June 1956. In 1986, Anders married Engineer Richard Benedict; the couple remained married until his death in 1999.

Shortly after the birth of her daughter in 1956, Anders took over the role of "Rita Malone" (popularized by Jayne Mansfield) in the West Coast touring production of the Broadway hit Will Success Spoil Rock Hunter?. In 1957, Anders had a much-publicized leading role in Paramount Pictures film Hear Me Good, opposite Hal March. She starred in four low-budget films that same year, The Dalton Girls, Calypso Heat Wave, The Night Runner and Escape from San Quentin.

Also in 1957, Anders landed the role of "Mike McCall" in the NTA Film Network and syndicated sitcom How to Marry a Millionaire. The series was based on the hit 1953 film of the same name (in which Anders appeared in a bit role) starring Betty Grable, Marilyn Monroe, and Lauren Bacall. Anders co-starred in the series with Barbara Eden and Lori Nelson. The first season of How to Marry a Millionaire was fairly successful and it was renewed for a second, abbreviated season. It was cancelled in 1959.

By the late 1960s, Anders' acting career had begun to wane. In 1968, she appeared as uncredited "glorified extra" in the film Airport (1970). To supplement her income between acting jobs, Anders took a job as a receptionist at Litton Industries. Her final acting role was a guest spot in the two part Gunsmoke episode "Waste", which aired late September and early October 1971.

In 1962, Anders was cast in the first English-language live action film adaptation of the 18th century French fairy tale Beauty and the Beast. In 1965, she appeared opposite Elvis Presley in the musical comedy Tickle Me. The following year, she appeared in the recurring role of "Alice" in the teen soap opera Never Too Young. Later that year, Anders had a supporting role in the B movie Women of the Prehistoric Planet. From 1967-68, she appeared in seven episodes of Jack Webb's Dragnet series on NBC, in which she played policewoman Dorothy Miller. She appeared in a recurring role on Lassie.

Anders retired from acting in 1972 in order to "live a normal life." She eventually became a customer relations coordinator at Litton Industries, where she remained until her retirement in 1994.

On October 28, 2012, Anders died in Encino, California, aged 78, from undisclosed causes.