| Official Name: | Gasa Dzong |
| Pushpin Map: | Bhutan |
| Pushpin Label Position: | bottom |
| Pushpin Map Caption: | Location in Bhutan |
| Subdivision Type: | Country |
| Subdivision Name: |  Bhutan |
| Subdivision Type1: | Admin. division |
| Subdivision Type2: | District |
| Leader Title: | Dzongdak |
| Unit Pref: | Imperial |
| Population Blank1 Title: | Ethnicities |
| Population Blank2 Title: | Religions |
| Timezone: | BTT |
| Utc Offset: | +6 |
| Coordinates: | 27.9039°N 89.7275°W |
| Elevation M: | 2850 |
Gasa Dzong༼མགར་ས།༽ or Gasa Tashi Tongmön Dzong near Gasa is the administrative center of Gasa Dzongkhag (district) in the northwestern region of Bhutan. The Dzong was built in the 17th century by Tenzin Drukdra the second Druk Desi over the site of a meditation place established by Drubthob Terkungpa in the 13th century. The Dzong was constructed as a bulwark against attacks from the north and named Tashi Tongmön Dzong. It was later expanded by the fourth Desi, Gyalse Tenzin Rabgye.[1] Inside the Guardian's Temple (Mgon Khang) he placed ritual object and performed the consecration ceremony.[2]
In January 2008 Gasa Dzong was badly damaged by fire.[3]
Legend has it that when Zhabdrung was making his way to Bhutan, the deity of Gasa traveled to Tsari Kibuthang in Tibet to greet him. The Zhabdrung blessed the deity with the new name of ''Trashi Thongmoen''. Thus, the Dzong was also given the same name in 1648, since the deity was its protector.[4] ་ The locals say that the entire landscape has the appearance of the image of Tsheringma (ཚེ་རིང་མ།), Goddess of long life, and the dzong, named Trashi Thongmon, is built on the chest of the image, which happens to be the local deity of Gasa.