Lorestan province is one of the 31 provinces of Iran. It is in the western part of the country in the Zagros Mountains and covers an area of 28,392 km2. Its capital is the city of Khorramabad. At the time of the National Census in 2006, the province had a population of 1,689,650 in 382,805 households. The 2011 national census counted 1,754,243 residents in 462,260 households. In 2014 it was placed in Region 4. At the most recent census in 2016, the population of Lorestan province had risen to 1,760,649 inhabitants in 509,025 households.

The Zagros Mountains are a long mountain range in Iran, northern Iraq, and southeastern Turkey. The mountain range has a total length of 1,600 km (990 mi). The Zagros range begins in northwestern Iran and roughly follows Iran's western border while covering much of southeastern Turkey and northeastern Iraq. From this border region, the range continues southeast under also the waters of the Persian Gulf. It spans the southern parts of the Armenian highlands, the whole length of the western and southwestern Iranian plateau, ending at the Strait of Hormuz. The highest point is Mount Dena, at 4,409 metres (14,465 ft).