Golestan province is one of the 31 provinces of Iran, located in the northeast of the country and southeast of the Caspian Sea. Its capital is the city of Gorgan, formerly called Esterabad until 1937. Golestan was split off from Mazandaran Province in 1997.

Golestan Province borders Turkmenistan to the north. One of the key border points between the two countries is Incheh Borun, which serves as a vital crossing point.

The province was made a part of Region 1 upon the division of the provinces into 5 regions, solely for coordination and development purposes, on 22 June 2014. The majority of its population are Shia Muslims.

Gulistan, Golestan, or Golastan translates to "gul-" meaning "flower" and "-stan" meaning "land" or "region." Golestan, therefore, literally means "land of flowers" in Iranian languages (e.g., Persian, Kurdish, and Mazandarani). This is a common toponym in countries with Persian linguistic roots (see Gulistan).

The capital of Gorgan derives its name from a wider region known historically as Gorgân (گرگان), Middle Persian Gurgān, and Old Persian Varkāna (in the Behistun Inscription) meaning "land of wolves". This is also the root of the Ancient Greek Ὑρκανία (Hyrkanía) and Latin Hyrcania. Wild wolves are still found in Golestan.

Human settlements in this area date back to 10,000 BC. Evidence of the ancient city of Jorjan can still be seen near the current city of Gonbad-e Kavus. It was an important city of Persia located on the Silk Road.

Under Achaemenid Iran, it seems to have been administered as a sub-province of Parthia and is not named separately in the provincial lists of Darius and Xerxes. The Hyrcanians, however, under the leadership of Megapanus, are mentioned by Herodotus in his list of Xerxes' army during the invasion of Greece.

In 2006, the Ministry of Education of Iran estimated the ethnic breakdown of the province to be: