Marquis de Seignelay, he entered the service of Cardinal Mazarin, becoming the administrator of his personal finances. On the cardinal's death he was appointed to the Council of Finance and in 1665 became controller general of the finances of the realm of Louis XIV. Colbert's economic policy was based on the development of industry, the restraint of salaries and the implementation of a series of protectionist measures as well as incentives for investment in the sector. In 1667 he had a code of civil procedure (Ordonnance civile) drawn up, while the publication of the first modern commercial code (Ordonnance du commerce)dates from 1673. Colbert's activity in the cultural field was very important: in 1664 he founded the Academy of Painting and Sculpture and in 1671 that of Architecture.

In 1666 the French Academy was set up in Rome, with the aim of providing French artists with the opportunity to study Italian art. This was the context for Colbert's journey to Italy, of which he left an interesting account in L'Italie en 1671. Relation d'un voyage du marquis de Seignelay suivie de lettres inédites à... et precedée d'une étude historique par Pierre Clement (Didier, Paris 1867). In the last years of his life Colbert's influence on Louis XIV was eclipsed by the greater political weight assumed by Francois-Michel Le Tellier, marquis de Louvois and secretary of state for war from 1666.