Valet de chambre (French pronunciation: ​[valɛ də ʃɑ̃bʁ]), or varlet de chambre, was a court appointment introduced in the late Middle Ages, common from the 14th century onwards. Royal households had many persons appointed at any time. While some valets simply waited on the patron, or looked after his clothes and other personal needs, itself potentially a powerful and lucrative position, others had more specialized functions. At the most prestigious level it could be akin to a monarch or ruler's personal secretary, as was the case of Anne de Montmorency at the court of Francis I of France. For noblemen pursuing a career as courtiers, like Étienne de Vesc, it was a common early step on the ladder to higher offices.

For some this brought entry into the lucrative court business of asking for favours on behalf of clients, and passing messages to the monarch or lord heading the court. Valets might supply specialized services of various kinds to the patron, as artists, musicians, poets, scholars, librarians, doctors or apothecaries and curators of collections. Valets comprised a mixture of nobles hoping to rise in their career, and those—often of humble origin—whose specialized abilities the monarch wanted to use or reward.

The title of valet enabled access to the monarch or other employer; the "chambre" originally referred to rooms such as the throne room, or the Privy chamber where the ruler conducted his more private meetings, but services extended to the bedroom as well. Sometimes, as in Spain and England, different bodies of valets were responsible for the bedroom and the daytime rooms. Often, the moment the ruler went outdoors a whole new division of staff took over.

From the late 14th century onwards the term is found in connection with an artist, author, architect, or musician's position within a noble or royal circle, with painters increasingly receiving the title as the social prestige of artists became increasingly distinct from that of craftsmen. The benefits for the artist were a position of understood status in the court hierarchy, with a salary, livery clothes to wear (in the early period at least), the right to meals at the palace, often in a special mess-room, and benefits such as exclusion from local guild regulations, and, if all went well, a lifetime pension. The valet would frequently be housed, at least when working in the palace, but often permanently. Lump-sums might be paid to the valet, especially to provide a dowry for a daughter; sons were often able to join the court as well.