Sant Celoni (Catalan pronunciation: [ˈsan səˈlɔni]) is a municipality in the comarca of the Vallès Oriental in Catalonia, Spain.

The municipality of Sant Celoni comprises the town center, the most populated (17,076 inhabitants, 2012), plus come other group of scattered nuclei.

The urban area of Pertegàs (260 inhabitants) is next to the town center, from which it is separated by the entrance road to Sant Celoni, connecting with the C-35 on the east side (Porta de Llevant).

Although it now occupies a peripheral situation, near its boundaries there is the church of Sant Martí de Pertegàs, which in fact was the original nucleus of the town.

In contrast to the depopulation caused by the abandonment of traditional activities (cultivation, grazing and those related to the exploitation of the forest), it is necessary to mention the appearance of different urbanizations within the Montnegre area from the second half of the twentieth century, which have gradually become nuclei of stable population: Can Coll (98 inhabitants), Cal Batlle (66) and the Boscos del Montnegre (237).

Sant Celoni is the translation from the Latin Sanctum Celedonium and Sancti Celedonii, which refers to Saint Celedonius.

There have been many variations on the name through the centuries: Sancti Celidonia, Sant Celdoni, Sent Salony, Sanseloni, San Celoni.