The economy of Bongaigaon is dominated by heavy industry and public sector undertakings (PSUs).
* **Indian Oil Corporation Limited (IOCL)**: The Bongaigaon Refinery is the most prominent industrial entity in the region, processing crude oil and producing petrochemicals. * **Northeast Frontier Railway (NFR)**: While not a traditional "company," the NFR operates a massive Carriage and Wagon Workshop in New Bongaigaon, making it one of the largest employers in the region. * **NTPC Limited**: Though technically located in nearby Salakati (Kokrajhar district), the Bongaigaon Thermal Power Project is deeply tied to the city's local economy and workforce.