Stevens, born Inger Stensland, in Stockholm, Sweden, was an insecure and often ill child. Her parents divorced while living in Sweden and she moved with her father to the United States. She attended high school in Manhattan, Kansas. At 16 she left home and started to work in New York City as a showgirl in low-budget performances. At the same time she took lessons at the Actors Studio.

Later she made appearances in commercials, plays and TV until she finally got her big chance in the movie Man on Fire, with Bing Crosby. Several roles in major films followed, but she had the greatest success with her leading role in the television series The Farmer's Daughter, and also with roles in TV episodes of series like The Twilight Zone, Bonanza and The Alfred Hitchcock Hour.

Inger Stevens committed suicide in Los Angeles, California with an overdose of sleeping pills. It then became known that from 1961 to her death she had been married to Ike Jones, a black American actor. Her first husband was Anthony Soglio, with whom she was married from 1955 to 1957.

She dated Burt Reynolds shortly before her suicide. To this day Reynolds politely refuses to discuss any aspect of his relationship with Stevens.