Odoardo (1738) — Niccolò Jommelli

Oedipe à Colone (1786) — Antonio Sacchini

Olimpia timida (1771) — Johann Friedrich Agricola

Oreste e Pilade (1772) — Johann Friedrich Agricola

Orfeo

Orfeo dolente (1616) — Domenico Belli

Orfeo ed Euridice

Orfeus und Eurydice (1683) — Johann Philipp Krieger

Orlando

Orlando finto pazzo (1714) — Antonio Vivaldi

Orlando finto pazzo - 1714 (1714) — Antonio Vivaldi

Orlando furioso (1727) — Antonio Vivaldi

Orlando furioso - 1727 (1727) — Antonio Vivaldi

Orphée (1690) — Louis Lully

Orphée aux enfers (1699) — Andre Campra

Orpheus and Euridice

Orpheus and Eurydice (1740) — Lampe Lampe

Orpheus von Thracien (1659) — Johann Jakob Löwe von Eisenach

Ottaviano in Sicilia (1696) — Francesco Ballarotti

Ottone in Italia (1679) — Francesco Maria Bazzani

Ottone in villa (1713) — Antonio Vivaldi

Ottone, re di Germania (1723) — George Frideric Handel