A sinfonietta is a work for orchestra that is generally considered to be smaller in scope than a full symphony. The word is sometimes also used to refer to small symphonic ensembles which are considered too large to be chamber ensembles.

There are many professional and amateur orchestras bearing the name "Sinfonietta", including:

• Chicago Sinfonietta
• See a list at website of Dutch chamber orchestra Sinfonietta Geleen

A number of composers have written works under this title:

• For the Sinfonietta of Leoš Janáček, see Sinfonietta (Janáček)
• For the Sinfonietta of Francis Poulenc, see Sinfonietta (Poulenc)
• For the Sinfonietta of Sergei Prokofiev, see Sinfonietta (Prokofiev)
• Lennox Berkeley's Sinfonietta
• Benjamin Britten's Sinfonietta
• Marcus Tristan Heathcock's Sinfonietta is his First Symphony
• Bernard Herrmann's Sinfonietta for String  Orchestra
• Paul Hindemith's Symphonietta (Little Symphony) in E-major
• E. J. Moeran's Sinfonietta
• Krzysztof Penderecki's Sinfonietta No. 1, for string orchestra and Sinfonietta No. 2, for clarinet and strings
• Max Reger's Sinfonietta in A major, op. 90
• Nikolai Rimsky-Korsakov's Sinfonietta on Russian Themes in A minor, Op. 31
• Alexander von Zemlinsky's Sinfonietta for orchestra. op. 23

José Pablo Moncayo "Sinfonieta"