Madhesh Province is a province of Nepal in the Terai region with an area of 9,661 km2 (3,730 sq mi) covering about 6.5% of the country's total area. It has a population of 6,126,288 as per the 2021 Nepal census, making it Nepal's most densely populated province and the smallest province by area. It borders Koshi Pradesh to the east and the north, Bagmati Province to the north, and India’s Bihar state to the south and the west. The border between Chitwan National Park and Parsa National Park acts as the provincial boundary in the west, and the Kosi River forms the provincial border in the east. The province includes eight districts, from Parsa in the west to Saptari in the east.

Koshi Province is the autonomous easternmost province adopted on 20 September 2015 by Constitution of Nepal. The province is rich in natural resources, tourist attractions, recreational activities, and natural beauty. The province covers an area of 25,905 km2 (10,002 sq mi), about 17.5% of the country's total area. With the industrial city of Biratnagar as its capital, the province includes major eastern towns of Birtamod, Sundar Haraincha, Damak, Dharan, Itahari, Triyuga Municipality and Mechinagar, and the Mount Everest, Kangchenjunga and Ama Dablam. Koshi River, the largest river of the nation, forms the province's western boundary. Under the First-past-the-post voting system issued by the Constituency Delimitation Commission, Nepal, the province hosts 28 parliamentary seats and 56 provincial assembly seats.