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.

In the English Royal Household the French term was used, whilst French was the language of the court, for example for Geoffrey Chaucer in the 1370s; but subsequently titles such as Groom of the Chamber, Groom of the Stool, and Groom of the Robes were used for people with different responsibilities. The "Grooms of the Privy Chamber" and of the "Stool" were more important posts because they involved closer access and were usually held by the well-born, often knights. The "Groom-Porter"'s job was to "regulate all matters to do with gaming" at court, providing the cards, and settling disputes.

Other countries used other terms: in Italian usually cameriere, in German-speaking courts Kammerjunker or Hofjunker were the usual titles, though it was Kammerer in the Austrian Habsburg court, and Kammerherr in Bavaria. In Russia Stolnik was broadly equivalent, until Peter the Great introduced new titles in 1722, after which the Камер-юнкер or kammerjunker came 11th out of 14 in the Table of Ranks. "Valet de chambre" also became used outside courts to refer to normal manservants.

The patron retained the services of the valet de chambre-artist or musician, sometimes exclusively, but often not. The degree to which valets with special skills were expected to perform the normal serving tasks of valets no doubt varied greatly, and remains obscure from at least the earlier records. Probably many were expected to be on hand for service on major occasions, but otherwise not often. The appointment gave the artist a place in the court management structure, under such officials as the Lord Chamberlain in England, or the Grand Master of France, usually via an intermediate court officer. In turn the valets were able to give orders to the huissiers or ushers, footmen, pages, and other ordinary servants.

There were some female equivalents, such as the portrait miniaturist Levina Teerlinc (daughter of Simon Bening), who served as a gentlewoman in the royal households of both Mary I and Elizabeth I, and Sofonisba Anguissola, who was court painter to Philip II of Spain and art tutor with the rank of lady-in-waiting to his third wife Elisabeth of Valois, a keen amateur artist. During the Renaissance, the regularly required artistic roles in music and painting typically began to be given their own offices and titles, as Court painter, Master of the King's Music and so forth, and the valets mostly reverted to looking after the personal, and often the political, needs of their patron. In fact Jan van Eyck, one of the many artists and musicians with the rank of valet in the Burgundian court, was already described as a painter as well as a valet.