Ollanda: see Francesco
Onofrio: San, the master's workshop at, [124]
Operai: of the Duomo, [115], [120]
Orcagna, [99]
Orvieto, [221]
Ottavio Farnese: the marriage of, [306]
Ovid, [299]
Oxford:
drawings at, anatomy students, [16];
after two destroyed frescoes, [166];
design for alterations at San Lorenzo, [198], [230]
Padua, [290]
Palla: Giovanni Battista della, [105]