Katihar district is one of the thirty-eight districts of Bihar state in India, and Katihar city is the administrative headquarters of this district. The district is a part of Purnia Division. It is prominently known for its Katihar Junction Railway Station, which is a Category A station on the Barauni–Guwahati line. It has been included in the Aspirational Districts Program of the Government of India since 2018, to improve its socio-economic indicators.

Katihar is a city situated in the eastern part of the state of Bihar in India. It is the regional headquarters of Katihar district. It is one of the important cities of Bihar. It is also a main stop on the Barauni–Guwahati line.