She later studied drama and voice at the Vienna Conservatory.
She first appeared on stage as a child actor, in various Max Reinhardt productions. At the outbreak of war in 1938, Palmer emigrated to the United States. She first performed on the stage in New York City, most notably in the 1942 production of The Moon Is Down.
She moved into film, helping to meet Hollywood"s demand for exotic foreign women for war films and films noir.
Her 1943 debut was in Mission to Moscow for Warner Brothers She continued in 1944 with Days of Glory, opposite Gregory Peck, and later that year, Lady on a Train.
In the 1950s, her film career declined and she went into radio, television and commercials. She even started her own production company, called Maria Palmer Enterprises.
In the early 1960s, Palmer hosted her own Los Angeles show, entitled "Sincerely, Maria Palmer".
In her later years, Palmer wrote a number of unproduced television screenplays, often using the pseudonym Eliot Parker White. In 1962, she played "Elsa" in the episode "The Immigrants" on Columbia Broadcasting System"s Rawhide. Palmer died of cancer in Los Angeles on 6 September 1981, the day after her 64th birthday.
She was buried at Forest Lawn Memorial Park, Hollywood Hills, California.
She trained as a dancer, and was a member of the Bodenwieser Ensemble.