RB Kolubara is a Serbian coal mining and smelting complex with headquarters in Lazarevac, Kolubara District. The mine has coal reserves amounting to 2.2 billion tonnes of lignite, one of the largest lignite reserves in Europe, and it produces 22.6 million tonnes of coal per year.

Lazarevac is a municipality of the city of Belgrade. As of 2022, the town has a total population of 27,635 inhabitants, while the municipal area has a total of 55,146 inhabitants.