Which painter was Michelangelo's first master?

Michelangelo’s first master was the Florentine painter Domenico Ghirlandaio.

In 1488, when Michelangelo was 13, he entered Ghirlandaio’s workshop as an apprentice. Ghirlandaio was one of Florence’s leading painters, known especially for frescoes, portraiture, perspective and figure drawing. His workshop was large and influential, and training there gave Michelangelo a practical foundation in painting and artistic production.

Michelangelo’s apprenticeship was brief, but it was an important first step. The following year, Lorenzo de’ Medici requested Ghirlandaio’s two best pupils for the Medici circle; Michelangelo and Francesco Granacci were sent. Michelangelo then studied among the artists and humanists connected with the Medici household, increasingly turning toward sculpture.

Botticelli, Leonardo da Vinci and Raphael are common distractors because all are major Renaissance names. They were not Michelangelo’s first master. He later worked in artistic environments shaped by several of them or their contemporaries, but Ghirlandaio is the single standard answer for his first formal apprenticeship.