Paul Saintenoy (19 June 1862 – 18 July 1952) was a Belgian architect, teacher, architectural historian, and writer.

Horta and Hankar's buildings laid the groundwork for the widespread development of the style called Art Nouveau in Belgium and France.

This became a preferred technique for the construction of retail shop windows and department stores, to encourage the practice of window-shopping.

Though Saintenoy was not nearly as famous as Horta, Hankar, Henry van de Velde or Gustave Serrurier-Bovy, the four most noteworthy practitioners of Art Nouveau in and from Belgium, he was well known at the turn of the century for his numerous buildings that use the style, most notably several smaller townhouses around Brussels, most of which still survive today and form part of the city's important heritage centred around the style.

With his interest in archaeology, from the time he served as the general secretary of the Royal Society of Archaeology, he embarked upon a teaching career in 1910, as a professor of the history of architecture at the Académie Royale des Beaux-Arts in Brussels, a position he occupied for some thirty years.