Borujerd is a city in the Central District of Borujerd County, Lorestan province in western Iran, serving as capital of both the county and the district.

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.