Eastern Nepal is the easterly region of Nepal, covering east, north and southern part of eastern Nepal.
Eastern Nepal prior to Septermber 2015 was made of 16 districts of Mechi, Koshi and Sagarmatha zone.
Mechi Zone: Panchthar District, Taplejung District, Ilam District and Jhapa District.
Koshi Zone: Bhojpur District, Morang District, Sankhuwasabha District, Dhankuta District, Sunsari District and Terhathum District.
Sagarmatha Zone: Solukhumbu District, Khotang District, Okhaldhunga District, Udayapur District, Siraha District and Saptari District,
covered an area of 28,456 Sqkm.
After September 2015, when Nepal adopted new constitution of Nepal 2015, Nepal also adopted new internal and regional boundaries of Nepal. As a result Eastern Nepal or Province No. 1's area changed from 28,456 Sqkm to 25,905 Sqkm, when 2 districts of Eastern Nepal, Siraha and Saptari was taken from Eastern Nepal and included in Province No. 2.