Flowers for Algernon has been adapted many times for different media including stage, screen and radio. These adaptations include:
- A 1961 television drama, The Two Worlds of Charlie Gordon, starring Cliff Robertson.
- A 1968 film, Charly, also starring Cliff Robertson, for which he won the Academy Award for Best Actor.
- A 1969 stage play, Flowers for Algernon by David Rogers.
- A 1978 stage musical, Charlie and Algernon by David Rogers and Charles Strouse.
- A 1991 radio play, Flowers for Algernon, for BBC Radio 4 starring Tom Courtenay.
- A 2000 television movie, Flowers for Algernon, starring Matthew Modine.
- A 2001 episode of the TV series "The Simpsons" titled "HOMR" has a plot similar to that of the novel.
- A 2002 Japanese drama, Algernon ni Hanataba wo for Fuji Television, starring Yūsuke Santamaria.
- A 2002 Marvel Spiderman Comic, "Flowers for Rhino"
- A 2006 French television movie, Des fleurs pour Algernon.
- A 2006 modern dance work, Holeulone, by French dancer and choreographer Karine Pontiès; it won the Prix de la Critique de la Communauté française de Belgique for best dance piece.
- A 2013 episode of the comedy TV series It's Always Sunny in Philadelphia in season 9 titled "Flowers for Charlie" which has a plot similar to that of the novel
- A 2013 episode of the comedy TV series The League in season 5 titled "Flowers for Taco" which has a plot similar to that of the novel
- A 2015 Japanese drama, Algernon ni Hanataba wo for Tokyo Broadcasting System, starring Yamashita Tomohisa.
- A 2015 podcast episode of Escape Pod , narrated by Dave Thompson
Further stage and radio adaptations have been produced in France (1982), Ireland (1983), Australia (1984), Poland (1985), Japan (1987, 1990), and Czechoslovakia (1988).