The swearing-in ceremony was attended by top leaders of the National Democratic Alliance (NDA), including Prime Minister Narendra Modi and Union Home Minister Amit Shah.
BJP leaders Samrat Choudhary and Vijay Sinha were sworn in as the Deputy Chief Minister of the state, which battles poverty and unemployment.
Nitish has now secured a place in the list of 10 longest serving Chief Ministers of the country.
Top 10 longest-serving CMs in India
1. Pawan Kumar Chamling, Sikkim: 24 years, ~165 days
2. Naveen Patnaik, Odisha: 24 years, 99 days
3. Jyoti Basu, West Bengal: 23 years, ~137 days
4. Gegong Apang, Arunachal Pradesh: 22 years, 8 months (for multiple terms)
5. Lal Thanhawla, Mizoram: 22 years: 60 days (across terms)
6. Virbhadra Singh, Himachal Pradesh: 21 years (across multiple terms)
7. Manik Sarkar, Tripura: 19 years, 363 days
8. Nitish Kumar, Bihar: 19 years, 93 days (cumulative)
9. M. Karunanidhi, Tamil Nadu: 18 years, ~362 days
10. Parkash Singh Badal, Punjab: 18 years, ~350 days (across terms)