Birendranath Sasmal was born in Chandibheti, Contai, in undivided Midnapore district in a Bengali Mahishya family.

He passed the Entrance Examination in 1900 from Contai High School, Tarakgopal Ghosh and Sashibhusan Chakraborty, two of his teachers had greatly influenced him.

[1] After finishing his college he went to England to study law at the Middle Temple; during this time he visited United States and Japan.

Social work and politics was of the paramount importance to him and he played a pivotal role as a relief worker during Midnapore floods of 1913, 1920, 1926 and 1933.

[3][3] During the Civil disobedience movement of 1930, while serving as a member of the committee appointed to enquire into the atrocities committed by the Midnapore district administration he was arrested.

[1][3] For political reasons, Midnapore district was proposed to divided into two by British Raj and Biren Sasmal started protesting against it.

[1][2][6][5] Sasmal played a leading role in the 1920 Calcutta Session of the National Congress and supported the resolution of non-cooperation movement of1921.

He joined the Calcutta Conference held under the auspices of the Congress Nationalist party to oppose Ramsay MacDonald's 'Communal Award'.

At the request of Pandit Madan Mohan Malavia, he contested in Central Legislative Assembly election from a two–district seat of Burdwan division and won it but he breathed his last before the result was announced.

[3] In 1924, when Birendranath Sasmal claimed the post of Chief executive officer of the Calcutta Corporation, an untoward situation occurred.

A battle took place between Subhas Chandra Bose and Birendranath Sasmal for the post of the Chief executive officer of Calcutta Municipal Corporation, which then dominated political life of Bengal.

Bose was ultimately choosen even though, Chittaranjan Das had originally proposed to reward the services of Sasmal by offering him the job, he soon backed out when he found out that the choice would offend the Kayastha clique of the city.

One of them went so far as to comment: ‘Will a keot from Midnapur come and rule in Calcutta?’ Sasmal asked his mentor Das two questions at a meeting of the Bengal Provincial Congress Committee (BPCC): '(1) Subhas Bose had been elected member and his brother Sarat Bose alderman of the Calcutta Corporation by the Swaraj party.

[9] Sasmal left the BPCC in utter humiliation and anger, and went into his legal practice and his control of local politics in Contai and Midnapore.

When his train was at Kharagpur he was misinformed that he had lost the national election of the Burdwan division, this news shocked him to an extreme extent which ended up causing him a great amount of emotional and Mental tension, although some of the well wishing co-passengers provided him with immediate medical attention.