Rajbiraj is a mid-sized municipality located in the south-eastern part of Madhesh Province, Nepal. It serves as the district headquarters of Saptari, a role it assumed in 1944 when the headquarters were transferred from Hanumannagar. The city was officially declared a municipality in 1959 and is currently ranked as the eighth largest city in its province.
The city is notably known as the "Pink City of Nepal" due to its urban design. In 1938, the township was planned based on the influence of Jaipur, India's "Pink City," making it the first township in Nepal to receive formal urban planning. Covering an area of 55.64 km2 and comprising 16 wards, Rajbiraj had a population of 70,803 according to the 2021 census.