- O. B. 5/334**
- Oberndörffer, David 5/772
- Obrecht (Hobrecht), Jacob 1/830, 1/1839, 1/2199, 2/145, 2/540, 2/1003, 2/1414, 2/1422, 2/1426, 2/1430, 2/1916, 2/2356, 3/454, 3/1374, 3/1803, 3/1804, 3/2229, 3/2258, 5/304, 5/328, 5/330, 5/335, 5/353, 5/357, 5/364, 5/377
- Ochsenkuhn, Sebastian 1/157
- Ockeghem (Oquegan), Johannes 2/972, 2/974, 2/1413, 2/1414, 2/1448, 2/1906, 2/1916, 3/442, 3/1353, 3/1374, 3/1801, 3/2240, 3/2241, 4/475, 5/330, 5/351, 5/357, 5/364, 5/365
- Ocker, Berend u. Catharina Arens 2/2067
- Odontius, Matthaeus 2/698
- Öglin (Oeglin), Erhard 1/683*, 2/749, 2/2082, 5/394
- Öhmin (Öhme), Dorothea 5/439**
- Öhmin (Öhme), Emanuel 5/439**
- Oeler, Conrad 2/146, 5/84
- Oelschlegel, Melchior 1/440, 1/662, 1/663, 1/664, 1/1471, 1/1472, 3/1502, 5/426
- Oesterreich, Georg 2/469, 2/1370
- Oesterreich, Michael 2/1371, 2/1372, 2/1372, 2/1374, 2/1375, 2/1376, 2/1377, 2/1378, 2/1379, 2/1380, 2/1381, 2/1383, 2/1383
- Ohr, Philipp von 2/155, 2/703, 2/1639, 2/1640, 3/1558
- Ohr, Philipp von (Erben) 1/1123
- Okel, C. 1/1354, 1/1355, 1/2228
- Oley, Johann Christoph 3/1744
- Olffen, Johann 1/1840
- Olthof, Statius 4/115
- Onslow, Georges 5/773, 5/774
- Opitz, Martin 1/1422, 2/1074, 3/557, 3/996, 3/1017, 5/47, 5/667
- Oppen, Hinrich v. 2/1161
- Oquegan (s. unter Ockeghem, Johannes)
- Orgosinus, Henricus 1/471
- Oridryus, Johannes 3/952
- Orlandini, Antonio 2/147*
- Ornitoparchus, Andreas 1/472, 1/2225, 5/416
- Orologio (Horologius), Alessandro 1/158, 1/393*, 2/2352
- Ortiz, Diego 3/2263
- Orto, Mabriano de 2/1413, 2/1916, 2/2347, 3/142, 3/1374
- Osculati, Giulio 1/1204, 2/1418, 2/1419, 3/1367, 5/319**
- Osiander, Lucas 1/632
- Osterberger, Georg 1/533, 1/534, 1/656, 1/983, 1/984, 1/1402, 1/1403, 1/1404, 1/1406, 2/69, 2/70, 2/71, 2/72, 2/73, 2/624, 2/1072, 2/2007, 2/2008, 5/137
- Osterberger, Georg (Wwe.) 2/61, 2/2009, 2/2010
- Ostia, Petrus de (= Fra Pietro d'Hostia) 5/314
- Oswald, Andreas 3/1745
- Oswald, Heinrich Siegmund 4/1053
- Othmayr, Caspar 1/159, 1/160, 1/161, 1/633, 1/1042, 2/148*, 2/341, 3/2234, 5/373
- Ottl, Hans 1/1082**
- Otthmar, V. 1/1373
- Ottho, Prinz von Hessen 1/266
- Otto, Georg 1/162, 1/163, 1/345, 1/634, 1/1155, 1/1156, 1/1157, 2/1789, 2/1790, 2/1791, 2/1792, 2/2270, 3/1804
- Otto, J. 1/297, 1/301*, 1/1097
- Otto, Stephanus 1/1043
- Otto, Valerius 2/149, 3/1521
- Overbeck, Catharine und Peter von 4/119
- Ovola 3/442, 3/452
