Quaraí is a Brazilian municipality in the state of Rio Grande do Sul, located on the border with Uruguay along the Rio Quaraí. It lies 590 km west of the state capital, Porto Alegre, northeast of Montevideo in Uruguay, and southeast of Alegrete.
The municipality covers an area of 3,147.63 km², making it one of the largest municipalities in the state, and sits at an elevation of 112 m. Its population is 22,607.