Belaka (Nepali: बेलका) is a municipality located in Udayapur District of Province No. 1 of Nepal. It is one of four urban municipalities located in Udayapur District. The total area of the municipality is 344.73 square kilometres (133.10 sq mi), and its population is 51458 as of the 2021 Nepal census. The municipality was formed on 10 March 2017, when the Government of Nepal announced 744 local level units as per the new constitution of Nepal 2015. The municipality was formed merging following former VDCs: Tapeshwari, Rampur Thoksila, Mainamaini and Katunjebawala.