John Forsell, born Carl Johan Jacob Forsell (6 November 1868 – 30 May 1941), was a prominent Swedish baritone, opera administrator and teacher of voice. He was the leading baritone of the Royal Swedish Opera (RSO) from 1896–1918, and thereafter sang roles periodically with the company until his last stage performance in 1938. From 1923-1939 he served as the director of the RSO. He also sang leading roles as a guest artist with opera companies internationally, drawing particular acclaim for his portrayal of the title character in Wolfgang Amadeus Mozart's Don Giovanni.
In 1899, Forsell was awarded the Litteris et Artibus and, a decade later, he was named a Hovsångare. The Royal Swedish Academy of Music awarded him membership in 1906.
Born in , Forsell was the son of Carl August Forsell, a sea captain, and Axeline Forsell (née Åberg). Before his singing career, he served in the Swedish Army; becoming a second lieutenant in 1890 and lieutenant in 1896. In 1897 he requested and was granted an honorable dismissal from the army, but continue to serve as a member of the Uppland Regiment reserves through 1901.
While serving in the army, he pursued voice studies with Julius Günther at the from 1892-1894. After graduating from college he studied singing further in Paris in 1895-1896 and later in Stockholm with Hedvig Willman and Signe Hebbe.
Forsell made his operatic debut at the Royal Swedish Opera, Stockholm, in 1896 as Figaro in The Barber of Seville. He would remain that opera house's premier baritone through 1918, and thereafter appeared only periodically at that theatre up until his retirement from the stage in 1938. He sang in several world premieres with the company, including Wilhelm Stenhammar's Tirfing (1898) and Andreas Hallén's Valdemarskatten (1899, the title role of Valdemar IV of Denmark). He also appeared in the Swedish premieres of Eugene Onegin (1903, title role), Tosca (1904, Scarpia), and Salome (1909, Jochanaan).