Katihar is a city located in the state of Bihar, India. It serves as the headquarters for both the Katihar district and the Katihar railway division of the Northeast Frontier Railway. Situated on the eastern bank of the Kari Kosi river, it ranks as the tenth largest city in Bihar by population.
The city is a significant economic, educational, and administrative center for the eastern region of Bihar. Historically, it functioned as an important metre gauge railway station within the Bengal Presidency, providing a vital link between North India and the regions of North Bengal and Northeast India. Today, its primary rail hub is Katihar Junction, which is a major station on the Guwahati - Barauni railway line.