Nitish Kumar, an Indian politician, has served as the 22nd Chief Minister of Bihar since February 2015, having previously held the office from 2005 to 2014 and for a brief period in 2000. He is Bihar’s longest-serving Chief Minister, now in his 9th term. His legislative career began in 1985 when he was elected as a Member of the Legislative Assembly (MLA) in Bihar. Nitish's political trajectory took a significant turn when he co-founded the Samata Party with George Fernandes in 1994, marking his emergence as a critical player in Bihar's political arena.

He is the leader of the Janata Dal (United). Previously, he served as a Union Minister as a Samata Party member until 2005 and Janata Dal from 1989 to 1994. He first entered politics as a member of the Janata Dal, becoming an MLA in 1985. In 1996, he was elected to the Lok Sabha and served as a Union Minister in the government of Atal Bihari Vajpayee, with his party joining the National Democratic Alliance. In 2003, his party merged into the Janata Dal (United) and Kumar became its leader. In 2005, the NDA won a majority in the Bihar Legislative Assembly, and Kumar became Chief Minister, heading a coalition with the Bharatiya Janata Party.

In the 2010 state elections, the governing coalition won re-election in a landslide victory. In 2013, Kumar broke with the BJP after Narendra Modi was named as their candidate for Prime Minister and formed the MAHAGATHBANDHAN, a coalition with the Rashtriya Janata Dal and Indian National Congress, joining the United Progressive Alliance. In 2014, Kumar resigned as Chief Minister after the party suffered severe losses in the Indian general elections. Later that year, the Mahagathbandhan won a large majority in the state elections. In 2017, Kumar broke with the RJD and returned to the NDA, leading another coalition with the BJP. In 2022, Kumar left the NDA, rejoining the Mahagathbandhan and UPA, and in 2024, he left the Mahagathbandhan once again and rejoined the NDA.

Nitish was briefly the Union Minister for Railways and Minister for Surface Transport and the Minister for Agriculture in the NDA government of Atal Bihari Vajpayee. In August 1999, he resigned following a train disaster for which he took responsibility. Later that year, he rejoined the Union Cabinet as Minister for Agriculture. From 2001 to 2004, he was again the Union Minister for Railways.

Having held the post of Chief Minister of Bihar for the 9th term, Kumar resigned and broke the Mahagathbandhan alliance with the RJD and Congress, rejoining the BJP-led NDA alliance, sparking a political crisis in the state. On the same day, he was sworn in as Chief Minister for the 9th time in 24 years.