Colonelganj is a town and a municipal board in Gonda district in the state of Uttar Pradesh, India.

In 1780, the king of Oudh State dispatched a British force, led by one Major Byng, to the area to subdue local rulers across the Gogra and bring them back under the nazims of Gonda and Bahraich.

[4] Writing in 1877, William Charles Benett described Colonelganj as a rapidly growing centre of trade, owing to its central location between Gonda, Bahraich, and Balrampur.

There was a thana, a dispensary, and a boys' school, which taught its 106 students in English, Urdu, and Hindi.

In the 2014 General Election for Members of Parliament, Shri Brij Bhushan Sharan Singh (Bhartiya Janta Party) was elected as Member of Parliament from Kaiserganj Constituency as colonelganj comes in this constituency.

In the 2017 General Election of Assembly, Shri Ajay Pratap Singh urf Lalla Bhaiya (Bhartiya Janta Party) was elected and made a member of the legislative assembly of Uttar Pradesh from Colonelganj.

Dr. Sanwal Prasad Singh (born 30 July 1949) was the first Dental Hygienist from King George Medical College Reg.