Fortunato Chelleri (originally: Keller, also: Kelleri, Kellery, Cheler) was a Baroque Kapellmeister and composer.
During his activity in Italy he composed mostly operas, such as L'Innocenza giustificata, premiered in Venice in 1711, La caccia in Etolia, premiered in Ferrara in 1715, on a libretto of Belisario Valeriano which was used by George Frideric Handel for Atalanta, and Amalasunta.
During his time in Germany and Sweden Chelleri composed instrumental and church music, including oratorios in Italian. Compositions for keyboard instruments, such as sixSonate di galanteria (Kassel), and six Sinfonie for strings were published. His oratorio in two parts Beatæ Mariæ Virginis (Würzburg, 1723) was reprinted by Garri Editions, Mühlheim, in 2003.