Châtel-Saint-Denis (French: [ʃɑtɛl sɛ̃ d(ə)ni]; Arpitan: Châtél, locally Tsathi [tsaˈθi] , or Châtél-Sent-Denis, locally Tsathi-Chin-Dèni) is a municipality and district capital of the district of Veveyse in the Canton of Fribourg in Switzerland .

Châtel-Saint-Denis has an area of 47.93 km2 (18.51 sq mi). Of this area, 22.37 km2 (8.64 sq mi) or 46.7% is used for agricultural purposes, while 20.26 km2 (7.82 sq mi) or 42.3% is forested. Of the rest of the land, 3.33 km2 (1.29 sq mi) or 7.0% is settled (buildings or roads), 0.27 km2 (0.10 sq mi) or 0.6% is either rivers or lakes and 1.65 km2 (0.64 sq mi) or 3.4% is unproductive land.

Of the built up area, housing and buildings made up 3.3% and transportation infrastructure made up 2.5%. Out of the forested land, 38.4% of the total land area is heavily forested and 3.8% is covered with orchards or small clusters of trees.