Smith showed a natural aptitude for singing at a young age. At 14, she started singing with a naval air station band led by Saxie Dowell. At 15, she got her first paying job with the Earl Bennett band.
Smith made her professional debut with Louis Prima in 1949 (the couple were married in 1953); Smith played the “straight guy” in the duo to Prima’s wild antics and they recorded many duets. These include Johnny Mercer’s and Harold Arlen’s “That Ol’ Black Magic,” which was a Top 20 hit in the US in 1958. In 1959, Smith and Prima were awarded the first-ever Grammy Award for Best Performance by a Vocal Group or Chorus for “That Ol’ Black Magic.” Her “dead-pan” act was a hit with fans. The duo followed up with the minor successes “I’ve Got You Under My Skin” and “Bei Mir Bist Du Schoen,” a revival of the 1937 Andrews Sisters hit. Smith and Prima’s act was a mainstay of the Las Vegas lounge scene for much of the 1950s.
Smith appeared with Prima in the 1959 film, Hey Boy! Hey Girl!, singing “Fever,” and also appeared in and sang on the soundtrack of the previous year’s Thunder Road. Her song in Thunder Road was “Whippoorwill.” Her first big solo hit was “I Wish You Love.” In 1961, Smith divorced Prima. She then signed with Reprise Records, where her musical director was Nelson Riddle. In 1965, she had Top 20 hits in the United Kingdom with an album of Beatles compositions, and a single, “You’re Breaking My Heart.” Her Reprise recordings have never been made available on CD.
In 1985, she made a comeback with I’m In Love Again (Fantasy Records). Her albums, Swing, Swing, Swing (2002), Keely Sings Sinatra (2001) for which she was Grammy nominated, and Keely Swings Count Basie Style with Strings (2002) garnered critical and fan acclaim.