[3] The film depicts the life and work of opera singer Maria Callas in her own words by using her interviews, letters, and performances to tell her story.

[4] Told through performances, TV interviews, home movies, family photographs, private letters and unpublished memoirs—nearly all of which have never been shown to the public—the film reveals the essence of an extraordinary woman who rose from humble beginnings in New York City to become a glamorous international superstar and one of the greatest artists of all time.

Opera singer Joyce DiDonato reads her letters and unpublished memoirs; Fanny Ardant narrates in the French version.

The website's critics consensus reads, "Maria by Callas offers an intimate look at the life of a brilliantly talented artist whose absorbing story matches the operatic heights reached by her work.

[11] Based on the film, the one-woman-show Maria Callas: Letters & Memoirs starring Monica Bellucci was shown at the Beacon Theatre in New York on 27 January 2023.