His father, Claude de Rouvroy (1607–93), was raised to the nobility by Louis XIII in 1635. The young Saint-Simon began his career with honourable military service (1691–1702); during this period he began a fragmentary diary. He fell out of royal favour, however, when he publicly opposed the policy of Louis XIV that reduced the power of the nobility. Saint-Simon was briefly connected with Louis, Duke de Bourgogne, who was dauphin from 1711 until his death in 1712. Saint-Simon then turned to Philippe II, Duke d'Orléans, who became regent for Louis XV in 1715. The regent appointed Saint-Simon to his council of regency (1715–18) and sent him on a diplomatic mission to Spain in 1721. Upon the regent's death in 1723, Saint-Simon retired from the court.

From 1729 to 1738 Saint-Simon annotated the Journal of Philippe de Courcillon, Marquis de Dangeau, a work that provided a framework for his own memoirs, begun about 10 years later. Saint-Simon produced a composite narrative of court life based upon his own memory and papers, oral and written testimony from his fellow courtiers, and other sources. Saint-Simon's life at court limited his perspective, however, and consequently his memoirs overemphasized personalities and petty intrigue. Nonetheless, he presents an unforgettable picture of the last years of Louis XIV and the regency period.