Olga, [825]

Olga, Countess, [720]

Olympia, [724]

Onegin, Eugen, [825]

Ophelia, [585]

Oracola, L', [686] ff.

Orestes, [18], [20], [804]

Orfeo, [8], [9], [13], [14]

Orfeo ed Euridice, [4], [5], [6], [8], [9], [20], [77], [493]

Orlando, [765]