Abandoned by his parents in Paris in 1794 at the height of the French Revolution, he worked as a kitchen boy at a cheap Parisian chophouse in exchange for room and board. In 1798, he was formally apprenticed to Sylvain Bailly, a famous pâtissier with a shop near the Palais-Royal. The post-revolutionary Palais Royal was a high profile, fashionable neighborhood filled with vibrant life and bustling crowds. Bailly recognized his talent and ambition. By the time he was prepared to leave Bailly, he could stipulate that he should be free to leave his new employer when a better offer came along. He opened his shop, the Pâtisserie de la rue de la Paix, which he maintained until 1813.

He did freelance work creating pieces principally for the French diplomat and gourmand Charles Maurice de Talleyrand-Périgord, but also other members of Parisian high society, including Napoleon. While working on his confections at many private kitchens, he quickly extended his culinary skills to main courses.

Napoleon was famously indifferent to food, but he understood the importance of social relations in the world of diplomacy. In 1804, he gave money to Talleyrand to purchase Château de Valençay, a large estate outside Paris. The château was intended to act as a kind of diplomatic gathering place. When Talleyrand moved there, he took Carême with him.

Carême was sent a test by Talleyrand: to create a whole year’s worth of menus, without repetition, and using only seasonal produce. Carême passed the test and completed his training in Talleyrand's kitchens. After the fall of Napoléon, Carême went to London for a time and served as chef de cuisine to the Prince Regent, later George IV. Returning to the continent he followed the invitation of Tsar Alexander I to come to St. Petersburg, where he lived so briefly he never prepared a meal for the Tsar before returning to Paris, where he was chef to banker James Mayer Rothschild.