Sistān and Balūchestān is one of the 30 provinces of Iran. It is in the southeast of the country, bordering Pakistan and Afghanistan and its capital is Zahedan, with a population of 420,000 inhabitants.

The province is the second largest in Iran, with an area of 181,600 sq km and a population of 2.1 million. It is also one of the most undeveloped, desolate and poor regions of Iran.

In the south and west of Sistān and Balūchestān, the people are mostly Balōchi and speak the Baluchi language. The name Balūchestān means "Land of the Balōchi" in Fārsi. Similarly, the Fārsi name Sistān comes from the Old Persian Sakastāna, meaning "Land of the Saka".

Ayatollah Sistani is from Sistān; he currently resides in Najaf, Iraq.