For the mountain range in northern Iran, see Alborz
Alborz Province (Persian: استان البرز, Ostan-e Alborz ) is one of the 31 provinces of Iran, centered in Karaj.
Alborz Province was formed by division of Tehran Province into two provinces, after the Parliamentary approval on June 23, 2010, and was introduced as 31st province of Iran.
Situated northwest of Tehran, the Province of Alborz has 4 counties, Karaj, Savojbolagh, Taleghan and Nazarabad. Karaj is the seat of the province. Alborz Province  is situated 20 km west of Tehran, at the foothills of the Alborz mountains, and is Iran's smallest province in area.