Adhir Ranjan Chowdhury, is an Indian politician who served as the leader of the Indian National Congress in the 17th Lok Sabha from 2019 to 2024 and the Member of Parliament from Berhampur from 1999 to 2024. He is also the current president of the West Bengal Pradesh Congress Committee. He has been the Chairperson of the Public Accounts Committee since 2019, Minister of State of Railways from 2012 to 2014, and a member of the West Bengal Legislative Assembly from 1996 to 1999.

Chowdhury joined the Indian National Congress party during the leadership of Rajiv Gandhi. In 1991, he contested the West Bengal Legislative Assembly election from the Nabagram constituency.

Chowdhury contested and won the 1999 Indian general election from Berhampur constituency.  Following his success, he was made the Congress president for the Murshidabad district. Between 1999 and 2000, he served as a Committee on Information Technology, and Railway Convention Committee member. Between 2000 and 2004, he served as a member of the Ministry of External Affairs Consultative Committee.

On 28 October 2012, he was inducted into the Union Ministry under Prime Minister Manmohan Singh as Minister of State for Railways. He became the president of the West Bengal Pradesh Congress on 10 February 2014.

In June 2019, he was elected as Congress Leader in Lok Sabha. On 26th July 2019, Chowdhury was appointed the chairman of the Seventeenth Lok Sabha Committee on Public Accounts.

He was appointed as president of the West Bengal Pradesh Congress Committee on 9th September 2020.

In a massive electoral upset, Chowdhury was defeated by TMC candidate Yusuf Pathan in the 2024 Indian General Elections.