| Arroio dos Ratos | |
| Settlement Type: | Municipality |
| Official Name: | O Município de Arroio dos Ratos The Municipality of Arroio dos Ratos |
| Pushpin Map: | Brazil |
| Pushpin Map Size: | 250 |
| Pushpin Map Caption: | Location in Brazil |
| Subdivision Type: | Country |
| Subdivision Name: |  Brazil |
| Subdivision Type1: | State |
| Subdivision Name1: | Rio Grande do Sul |
| Subdivision Type2: | Mesoregion |
| Subdivision Name2: | Metropolitana de Porto Alegre |
| Subdivision Type3: | Microregion |
| Subdivision Name3: | Porto Alegre |
| Leader Title: | Mayor |
| Leader Name: | Luciano Leites Rocha |
| Leader Party: | PSB |
| Established Title: | Founded |
| Established Date: | 28 December 1964 |
| Area Total Km2: | 425.210 |
| Population Demonym: | arroio-ratenses or ratenses |
| Population As Of: | 2020 [1] |
| Population Total: | 14,177 |
| Population Density Km2: | auto |
| Timezone: | BRT |
| Utc Offset: | -3 |
| Coordinates: | -30.0769°N -51.7289°W |
| Elevation M: | 69 |
| Area Code: | +55 51 |
| Postal Code Type: | Postal Code |
| Postal Code: | 96740-000 |
| Website: | Arroio dos Ratos, Rio Grande do Sul |
Arroio dos Ratos is a municipality in the Brazilian state of Rio Grande do Sul. Thanks to its soil, is nationally known as the National Cradle of the Coal industry. The city is also known as the National Capital of the Watermelon.