Born Suzanne Lorraine Burce in Portland, Oregon, she sang on the radio as a child, and performed in theater before her film career began in 1944. She appeared in her first film, Song of the Open Road (1944), at age 15. Her first MGM musical was Holiday in Mexico (1946), which brought her to the public's attention, and she was later billed as the co-star in several films including A Date with Judy (1948), and Nancy Goes to Rio (1950).

Powell got the chance to sing and dance with Fred Astaire in Royal Wedding (1951), when she was brought in as a replacement for both June Allyson and Judy Garland. Her best known film is probably Seven Brides for Seven Brothers (1954), which gave her the opportunity to play a more mature character than previous films. Her other films include: Rich, Young and Pretty (1951), Small Town Girl (1953), Three Sailors and a Girl (1953), Athena (1954), Deep in My Heart (1954), Hit the Deck (1955), and The Girl Most Likely (1957).

By the end of the 1950s, Hollywood musicals began to lose popularity, and her film career ended. Since then Powell has continued to work in television, radio, and live performances. Her stage roles include the touring productions of South Pacific, The Sound of Music, Oklahoma!, My Fair Lady, Carousel, The Girl Next Door and How She Grew, and Irene, in which she made her Broadway debut, following Debbie Reynolds in the title role.

During the 1960s and 1970s Powell appeared regularly on television. For example, she did a stint as one of the What's My Line? Mystery Guests on the popular Sunday Night CBS-TV program. Later, Powell appeared as a guest panelist on the same show.

Today, Powell enjoys very good health and lives in Connecticut, with her fifth husband, former child actor Dick Moore. She still acts and performs to the present day, most recently in a 2002 episode of Law & Order: Special Victims Unit.

She has four children from her first two marriages.