Syed Nazrul Islam was born in 1925 at Jamodal Dampara in Kishoreganj district.

Syed Nazrul Islam was a lawyer, politician and the acting President of the Provisional Government of Bangladesh at Mujibnagar.

He obtained his MA degree in History in 1947 and LLB in 1953 from the Dhaka University. He took active part in politics in his student life, and was the vice president of Salimullah Muslim Hall Student Union (1946-47) and secretary of Muslim Student League. He was the captain of the Dhaka University cricket and hockey team and secretary of games and sports of Dhaka University Central Students Union (DUCSU).

Syed Nazrul Islam successfully competed in the Pakistan Central Superior Service in 1949 and joined as an officer in the Department of Taxation. He resigned from government service in 1951 to join Anandamohan College (Mymensingh) as Professor of History. Subsequently he joined the Mymensingh district bar. He took active part in the language movement as a member of the all party Action Committee.

Syed Nazrul started his political career as an activist of awami league. He was elected president of Mymensingh district unit of the party in 1957. Syed Nazrul Islam was the senior vice president of central committee of Awami League from 1964 to 1972. He continued to hold the responsibility of the acting president of Awami League (1966-1969) following the confinement of the party chief Sheikh Mujibur Rahman during the movement with six-point programme. As one of the leaders of the Democratic Action Committee he played an important role in the anti-Ayub movement in 1969. He was a member of the Awami League delegation to the Round Table Conference convened by President mohammad ayub khan at Rawalpindi (1969).

Syed Nazrul Islam was elected member of the Pakistan National Assembly from Mymensingh in 1970, and was elected deputy leader of the Awami League parliamentary party. He officiated as acting president of Awami League after the arrest of Bangabandhu on 25 March 1971.

Syed Nazrul Islam was the Vice-President of the Mujibnagar Government formed on 10 April 1971, and in absence of the President Sheikh Mujibur Rahman he pioneered the war of liberation as Acting President.

Syed Nazrul Islam was elected member of the jatiya sangsad from Mymensingh in 1973. He was again elected deputy leader of the Awami League parliamentary party in the Sangsad. He was a member of the cabinet of Bangabandhu in charge of Ministry of Industry. With the introduction of one-party presidential form of government in the country in 1975 Nazrul Islam was made the Vice President and also the vice chairman of bangladesh krishak sramik awami league (BAKSAL).

Syed Nazrul Islam was arrested on 23 August and kept confined in the Dhaka central jail. He was ruthlessly killed inside the jail on 3 November 1975. He lies buried at Banani graveyard.