Hazarika was born on 8 September 1926 to Nilakanta and Shantipriya Hazarika in Sadiya, Assam. His father was originally from Nazira, a town located in Sivasagar district. The eldest of ten children, Bhupen Hazarika (as also his siblings) was exposed to the musical influence of his mother, who exposed him to lullabies and traditional Music of Assam. His father moved to the Bharalumukh region of Guwahati in 1929, in search of better prospects, where Bhupen Hazarika spent his early childhood. In 1932 his father further moved to Dhubri, and in 1935 to Tezpur. It was in Tezpur that Bhupen Hazarika, then 10 years of age, was discovered by Jyotiprasad Agarwala, the noted Assamese lyricist, playwright and the first Assames Filmmaker and Bishnu Prasad Rabha, renowned Assamese artist and revolutionary poet, where he sang a Borgeet (the traditional classical Assamese devotional songs written by Srimanta Sankardeva and Sri Sri Madhabdeva), taught by his mother at a public function. In 1936, Bhupen Hazarika accompanied them to Kolkata where he recorded his first song at the Aurora Studio for the Selona Company. His association with the icons of Assamese Culture at Tezpur was the beginning of his artistic growth and credentials. Subsequently, Hazarika sang two songs in Agarwala's film Indramalati (1939): Kaxote Kolosi Loi and Biswo Bijoyi Naujawan at the age of 12. He wrote his first song, Agnijugor Firingoti Moi at the age of 13 and he was well on his way to becoming a lyricist, composer and singer.
He studied at Sonaram High School at Guwahati, Dhubri Government High School and matriculated from Tezpur High School in 1940. He completed his Intermediate Arts from Cotton College in 1942, and his BA (1944) and MA (1946) in Political Science from Banaras Hindu University. For a brief period he worked at All India Radio, Guwahati when he won a scholarship from Columbia University and set sail for New York in 1949. There he earned a Ph.D. (1952) on his thesis "Proposals for Preparing India's Basic Education to use Audio-Visual Techniques in Adult Education. In New York Bhupen Hazarika befriended Paul Robeson- a prominent civil rights activist, who influenced him in his song Bistirno parore which is based on the imagery and theme of Robeson's Ol' Man River. This song is translated in various Indian languages, including Bengali and Hindi (by the artist himself), and is still popular. Being inspired from some other foreign ones, he also composed several other songs in Indian languages. He was exposed to the Spiritual, and the multi-lingual version of We are in the Same Boat Brother became a regular feature in his stage performance. At Columbia University, he met Priyamvada Patel, whom he married in 1950. Tez Hazarika, their only child, was born in 1952, and he returned to India in 1953.
Hazarika began close association with the leftist Indian People's Theatre Association soon after returning from the USA in 1953 and became the Secretary of the Reception Committee of the Third All Assam Conference of IPTA, held in Guwahati in 1955. After completing his MA he briefly worked at the All India Radio station at Guwahati before embarking for his doctoral studies at Columbia University. Soon after completing his education, he became a teacher at the Gauhati University. He was elected the President of the Asam Sahitya Sabha in 1993.
He met Kalpana Lajmi in the 1970s and they made the film Ek Pal (' at the Internet Movie Database) (1986). Subsequently, Lajmi began assisting him professionally and personally till the end of his life. In the period after the release of Ek Pal (1986) until his death, Bhupen Hazarika mainly concentrated on Hindi films, most of which were directed by Kalpana Lajmi. Ek Pal (1986), Rudaali (1993) and Daman: A Victim of Marital Violence (2001) are major films this period. Many of his earlier songs were re-written in Hindi and used as played-back songs in these films. These songs tried to cater to the Hindi film milieu and their social activist lyrics were browbeaten into the lowest common denominator. He served as an MLA (Independent) during 1967-72 in the Assam Legislative Assembly from Nauboicha Constituency. He contested as a Bharatiya Janata Party candidate in the 2004 Lok Sabha elections from the Guwahati constituency, which he lost to the INC candidate Kirip Chaliha.
As a singer, Hazarika was known for his baritone voice and diction; as a lyricist, he was known for poetic compositions and parables which touched on themes ranging from romance to social and political commentary; and as a composer, for his use of folk music. In a poll conducted in Bangladesh, his song, Manush Manusher Jonno (Humans are for humanity)' was chosen to be the second most favourite number after the National anthem of Bangladesh. Some of his most famous compositions were adaptations of American Black Spiritual that he had learned from Paul Robeson, whom he had befriended during his years in New York City in the early 1950s.
Hazarika was hospitalized in the Kokilaben Dhirubhai Ambani Hospital and Medical Research Institute in Mumbai in 2011. He was admitted to the intensive care unit on 30 June 2011. He died of multi-organ failure on 5 November 2011. His body lay in state at Judges Field in Guwahati and cremated on 9 November 2011 near the Brahmaputra river in a plot of land donated by Gauhati University. His funeral was attended by an estimated half a million people.