He spent most of his childhood in Rome. His talent as an artist revealed itself early and during this period he acquired a love of Italian painting and music, which he never lost. In 1782 his family returned to Paris, where, through the connections of his father's employer Louis-Auguste le Tonnelier, Baron de Breteuil, Minister of the King's Household, Gérard was admitted to the Pension du Roi, a small teaching establishment for young artists which had been founded by the Marquis de Marigny. After 18 months he entered the studio of the sculptor Augustin Pajou, where he remained for two years, before transferring to that of the painter Nicolas-Guy Brenet. He became a pupil of David in 1786 and quickly found special favour with his master.
In 1789 Gérard competed for the Prix de Rome and his entry, Joseph Revealing himself to his Brethren (Angers, Mus. B.-A.), was placed second; the winner was Girodet. He did not submit in 1790, being preoccupied with his father's illness and death "after which he returned to Italy with his mother and two younger brothers. Back in Paris by mid-1791 he became David's assistant in the painting of the Death of Le Pelletier de Saint Fargeau (destr.) in 1793 and the following year won first prize in the National Convention's competition on the theme of its historic session of 10th of August 1792 (prize drawing, Paris, Louvre; unfinished canvas, London, priv. col.). Although the project lapsed, his success secured him lodgings and a studio in the Louvre. The design was much praised by David "its composition was inspired by his own Oath of the Jeu de Paume (never completed) and through his influence Gérard was spared military service, though only at the cost of sitting on the Revolutionary Tribunal. (He avoided most, if not all, of its sanguinary sessions by feigning illness.).
On the death of his mother in 1793, Gérard married her sister and assumed responsibility for his youngest brother.