Bihar Population, According to the latest data from the Census of India, the population of Bihar, a state in eastern India, is approximately 125 million as of 2021. Bihar is the third most populous state in India and has a diverse population with people from various cultural and linguistic backgrounds. The capital of Bihar is Patna, which is one of the oldest continuously inhabited cities in the world. The state is known for its rich cultural heritage, with many ancient temples and monasteries located throughout the region. It is also an important agricultural state, with a large portion of the population involved in farming and related activities.