Três de Maio (English: "Third of May") is a Brazilian municipality in the state of Rio Grande do Sul. It is located at 27°45′09″S 54°14′37″W / 27.752602°S 54.243707°W.
It has an area of 422,2 km². It is located 343 m over sea level. As of 2014 its population was estimated to be 24,478 inhabitants. Its climate is mild with temperatures of 20 °C (68 °F) to 35 °C (95 °F) in summer and 0 (32 °F) to 15 °C (59 °F) in winter.
Supermodel Gisele Bündchen was born in Três de Maio.