This essay examines the role of ancient Egypt in courtly masquerades under François Ier (r. 1515–47). It opens with an analysis of the iconography of a sphinx costume that was designed by Francesco Primaticcio (1504/05–1570) and worn by the king and one of his favorite courtiers, Cardinal Jean de Lorraine (1498–1550), at a wedding celebration held in 1546. Two other costume drawings by the same artist are discussed next, and the first printed French translation of Horapollo’s Hieroglyphica, which was published in Paris in 1543, is identified as their source. In examining their strange aesthetic and multiple layers of meaning, this study considers how these costumes were symptomatic of a broader French Renaissance fascination with concealed truth and how, as conveyors of veiled messages, they were meant to spark lofty discussions and demonstrate the French court’s sophistication.