Sīstān, also known as Scythia, Sijistān, and Sākāstān (Persian/Baloch/Pashto: literally "land of the Saka or Scythians"), is a historical region in present-day eastern Iran (Sistan and Baluchestan Province), southern Afghanistan (Nimruz, Kandahar, and Zabul Province), and the Nok Kundi region of Balochistan (western Pakistan).

At times, the Saka territory encompasses areas as far east as Minnagara on the Indus River, in southwestern Sindh province of present-day Pakistan.

Sistan is a part of the region of ancient Ariana.

The Saffarids, one of the early Iranian dynasties of the Islamic era, were originally from Sistan.