This article traces the early reception of Ludovicus Decus Regnantium, the most common Proper Office for Saint Louis, King of France, canonized in 1297. It is generally considered a Dominican Office thought to have been produced on commission by the Dominican, Arnaud DuPrat, after his Order instituted Louis’ feast day. A number of factors confuse this attribution, including the existence of an earlier, rare Office for Louis, Nunc Laudare. A close examination of the extant evidence for the attribution and early reception of the Office leads to the conclusion that the Office was not celebrated by most, or even many, of the Dominican convents in France. It can thus be better understood in its Parisian and royal milieu within the context of the close relationship between the royal court of Philip the Fair (r. 1285–1314) and the Dominican convent of the Rue St-Jacques in Paris.