Robert de Cotte (1656 – 15 July 1735) was a French architect-administrator. He introduced the Rococo style. He was a pupil of Jules Hardouin-Mansart. He later became his teacher's brother-in-law and his collaborator. De Cotte married Hardouin-Mansart's sister. After Hardouin-Mansart's death, de Cotte completed his unfinished projects. These included the royal chapel at Versailles and the Grand Trianon.