Itahari (Nepali: ईटहरी) is a sub-metropolitan city in the Sunsari District of Koshi Province in Nepal.

Itahari city has grown as an important business hub of eastern Nepal.

It is one of the cities of the Greater Birat Development Area which incorporates the cities of Biratnagar-Itahari-Gothgau-Biratchowk-Dharan[1] primarily located on the Koshi Highway in Eastern Nepal, with an estimated total urban agglomerated population of 804,300 people living in 159,332 households.

[2] According to the Ministry of Federal Affairs and Local Development, Itahari has an area of 93.78 square kilometres (36.21 sq mi) with 140,517 people living in 33,794 individual households as of Census of Nepal 2011.

The largest ethnic group is Tharu, who makes 19% of the population, Hill Brahman and Chhetri comes to second and third with 17% each.