| Ametista do Sul | |
| Nickname: | O município que Brilha |
| Settlement Type: | Municipality |
| Subdivision Type: | Country |
| Subdivision Name: | Brazil |
| Subdivision Type1: | State |
| Subdivision Name1: | Rio Grande do Sul |
| Subdivision Type2: | Mesoregion |
| Subdivision Name2: | Noroeste Rio-grandense |
| Subdivision Type3: | Microregion |
| Subdivision Name3: | Frederico Westphalen |
| Leader Title: | Mayor |
| Leader Name: | Jadir José Kovaleski |
| Leader Party: | PP |
| Established Title: | Founded |
| Established Date: | March 20, 1992 |
| Area Total Km2: | 93,704 |
| Elevation M: | 505 |
| Population As Of: | 2022[1] |
| Population Total: | 7,650 |
| Population Density Km2: | auto |
| Timezone1: | BRT |
| Utc Offset1: | -3 |
| Coordinates: | -27.3608°N -53.1819°W |
| Website: | https://ametistadosul.rs.gov.br/ |
| Blank Name Sec1: | HDI |
| Blank Info Sec1: | 0.754 |
| Blank1 Name Sec1: | GDP |
| Blank1 Info Sec1: | R$ 41,493,000 |
| Blank2 Name Sec1: | GDP per capita |
| Blank2 Info Sec1: | R$ 5,161.00 |
Ametista do Sul (pronounced as /pt/,) is a municipality in the state of Rio Grande do Sul, Brazil. It borders Planalto, Frederico Westphalen, Cristal do Sul, Rodeio Bonito and Iraí. The municipality is known for the amethyst mines in the area. The center of town has a pyramid that the interior base walls (3 meters) are lined with amethyst. The opposing Catholic Church interior walls (6 meters) are covered with amethyst.
The community has several amethyst mines active. There is a museum dedicated to the industry. There are vineyards with older unproductive mines converted to wine cellars. There are stores and other outlets to purchase amethyst and other stones.