Dasht-e Kavir (Central Desert), also known as Kavir-e Namak or Great Salt Desert is a large desert lying in the middle of the Iranian Plateau. It is about 800 kilometers (497 mi) long and 320 kilometers (198 mi) wide with a total surface area of about 77,600 km² (~30,000 mi²).
The area of this desert stretches from the south hillside of Alborz mountain range in the north-west to the Dasht-e Lut ("Emptiness Desert") in the south-east and is partitioned between the Iranian provinces of Khorasan, Semnan, Tehran, Isfahan and Yazd. It is named after the salt marshes (kavirs) located there.

The Dasht-e Kavir's climate is almost rainless and the area is very arid. Temperatures can reach 50 °C in summer, and the average temperature in January is 22 °C. Day and night temperatures during a year can differ up to 70 °C. Rain usually falls in winter.