| Master of the Pala Sforzesca | — | 1401–1501 | 5 |
| Master of the Pacully collection | — | 1500 | 2 |
| Master of the Osservanza | — | 1410–1450 | 12 |
| Master of the Orléans Triptych | — | — | 1 |
| Master of the Once Mil Vírgenes | Spain | — | 3 |
| Master of the Oberaltaich Man of Sorrows | — | — | 1 |
| Master of the Novgorod School | — | — | 6 |
| Master of the Nativity of Castello | — | 1400–1500 | 10 |
| Master of the Murano Gradual | — | 1425–1475 | 1 |
| Master of the Münster Death of Saint Nicholas | Germany | 1490 | 1 |
| Master of the Munich Marian Panels | Germany | 1401–1499 | 1 |
| Master of the Munich Arrest of Christ | — | — | 1 |
| Master of the Moscow school (icons) | — | — | 16 |
| Master of the Morrison Triptych | Southern Netherlands | 1480–1520 | 3 |
| Master of the Mornauer Portrait | Germany | 1500 | 3 |
| Master of the Monogram TK | — | — | 2 |
| Master of the Monogram IDM | — | 1564–1635 | 2 |
| Master of the Miller Tondo | — | 1478–1530 | 2 |
| Master of the Medici Banquet Decanters | — | 1670 | 2 |
| Master of the Mass of Saint Gregory | Germany | — | 1 |
| Master of the Martyrs of Saints | — | 1480–1505 | 1 |
| Master of the Martyrdom of the Two Saint Johns | — | — | 1 |
| Master of the Mansi Magdalen | — | 1490–1530 | 7 |
| Master of the Magdalen | — | 1250 | 7 |
| Master of the Madonna of Benda | — | 1500 | 1 |
| Master of the Lyversberger Passion | Germany | 1500–1500 | 2 |
| Master of the Lille Adoration | Habsburg Netherlands | 1490–1530 | 1 |
| Master of the Life of the Virgin | Germany | 1500–1500 | 10 |
| Master of the Life of Saint John the Baptist | — | 1250 | 1 |
| Master of the Legend of the Magdalene | Habsburg Netherlands | 1480–1537 | 13 |
| Master of the Legend of St. Augustine | — | — | 1 |
| Master of the Legend of Saint Lucy | Habsburg Netherlands | 1430–1506 | 5 |
| Master of the Legend of Saint Catherine | Habsburg Netherlands | — | 4 |
| Master of the Legend of Saint Barbara | Kingdom of the Netherlands | 1470 | 3 |
| Master of the Lanckoronski Annunciation | — | — | 1 |
| Master of the Krumlov Madonna | — | 1400–1500 | 1 |
| Master of the Housebook | Holy Roman Empire | 1450–1500 | 5 |
| Master of the Holy Kinship the Younger | — | 1450–1515 | 1 |
| Master of the Holy Kinship the Elder | Germany | 1400–1500 | 4 |
| Master of the Holy Blood | Southern Netherlands | 1480–1524 | 4 |
| Master of the High Altar of Saint Jacob's in Nuremberg | — | — | 1 |
| Master of the Heisterbach Altar | — | 1500–1500 | 3 |
| Master of the Hartford Still Life | — | 1600–1700 | 1 |
| Master of the Habsburgs | — | 1450–1550 | 2 |
| Master of the Griselda Legend | Republic of Siena | 1500 | 4 |
| Master of the Greek school | — | — | 2 |
| Master of the Gothic Buildings | Italy | — | 1 |
| Master of the Gathering of the Manna | — | 1500–1500 | 1 |
| Master of the Games | — | — | 2 |
| Master of the Furies | — | 1505–1700 | 1 |
| Master of the Friedrich Altar of 1447 | — | — | 1 |
| Master of the Franciscan Crucifixes | — | — | 2 |
| Master of the Fogg Pietà | — | 1300–1400 | 4 |
| Master of the Figdor Deposition | — | 1480–1500 | 1 |
| Master of the Fiesole Epiphany | — | 1430–1500 | 1 |
| Master of the Female Half-Lengths | Southern Netherlands | 1501–1501 | 21 |
| Master of the Embroidered Foliage | Southern Netherlands | 1450–1600 | 2 |
| Master of the Drapery Studies | Germany | 1500 | 8 |
| Master of the Dominican Effigies | Italy | 1300–1400 | 9 |
| Master of the Dinteville Allegory | — | — | 1 |