Mookerjee was born on July 6, 1901 in Calcutta, a major Indian city and capital of Bengal. His father was Sir Ashutosh Mukherjee, a well respected advocate in Bengal, who became the Vice-Chancellor of the University of Calcutta, and his mother was Lady Jogmaya Devi Mookerjee.
Mookerjee obtained his degrees from the University of Calcutta. He graduated in English securing the first position in first class in 1921 and also did MA in 1923 and BL in 1924. He became a fellow of the Senate in 1923. He enrolled as an advocate in Calcutta High Court in 1924 after his father’s death. Subsequently he left for England in 1926 to study in Lincoln’s Inn and became a barrister in 1927. At the age of 33, he became the youngest Vice-Chancellor of the University of Calcutta (1934), and held the office till 1938.
He was elected as member of the Legislative Council of Bengal, as an Indian National Congress candidate representing Calcutta University but resigned next year when Congress decided to boycott the legislature. Subsequently, he contested the election as an independent candidate and got elected. He was the Finance minister of Bengal Province during 1941-42.
He emerged as a spokesman for Hindus and shortly joined Hindu Mahasabha and in 1944, he became the President. Mookerjee was not anti-Muslim, but a Hindu political leader who felt the need to counteract the communalist and separatist Muslim League of Muhammad Ali Jinnah, who were demanding either exaggerated Muslim rights or a Muslim state of Pakistan.
Mookerjee adopted causes to unite Hindu voices, and protect Hindus against what he believed to be the communal propaganda and the divisive agenda of the Muslim League. To Mookerjee, the Muslims were a minority and thus could not in any reasonable system be given a status superior to the majority Hindu masses. Mookerjee and his future followers would always cite inherent Hindu practices of tolerance and communal respect as the reason for a healthy, prosperous and safe Muslim population in the country in the first place.
Mookerjee was initially a strong opponent of the Partition of India, but following the communal riots of 1946-47, Mookerjee strongly disfavored Hindus continuing to live in a Muslim-dominated state and under a government controlled by the Muslim League.
On 11 February 1941 S P Mookerjee told a Hindu rally that if Muslims wanted to live in Pakistan they should "pack their bag and baggage and leave India... ... (to) wherever they like" .
Mookerjee supported the partition of Bengal in 1946 to prevent the inclusion of its Hindu-majority areas in a Muslim-dominated East Pakistan; he also opposed a failed bid for a united but independent Bengal made in 1947 by Sarat Bose, the brother of Subhas Chandra Bose and Huseyn Shaheed Suhrawardy, a Bengali Muslim politician.
He wanted the Hindu Mahasabha not to be restricted to Hindus alone or work as apolitical body for the service of masses. Following the assassination of Mahatma Gandhi by a Hindu fanatic, the Mahasabha was blamed chiefly for the heinous act and became deeply unpopular. Mookerjee himself condemned the murder and left the party.
Prime Minister Jawaharlal Nehru inducted him in the Interim Central Government as a Minister for Industry and Supply. Mookerjee was widely respected by many Indians and also by members of the Indian National Congress, and Sardar Vallabhbhai Patel, one of its chief leaders.
But on issue of the 1949 Delhi Pact with Pakistani Prime Minister Liaqat Ali Khan, Mookerjee resigned from the Cabinet on April 6, 1950. Mookerjee was firmly against Nehru’s invitation to the Pakistani PM, and their joint pact to establish minority commissions and guarantee minority rights in both countries. He wanted to hold Pakistan directly responsible for the terrible influx of millions of Hindu refugees from East Pakistan, who had left the state fearing religious suppression and violence aided by the state. Mookerjee considered Nehru’s actions as appeasement, and was hailed as a hero by the people of West Bengal.
After consultation with Madhav Sadashiv Golwalkar, leader of the Rashtriya Swayamsevak Sangh, Mookerjee founded the Bharatiya Jana Sangh (Indian People’s Union) on October 21, 1951 at Delhi and became its first President.
The BJS criticized favoritism to India’s Muslims by the Nehru administration, and promoted free-market economics as opposed to the socialism in Nehru’s economic and social policies. The BJS also favored a uniform civil code for both Hindus and Muslims, want to ban cow slaughter and end the special status of Muslim-majority Jammu and Kashmir. The BJS founded the Hindutva agenda which became the wider political expression of India’s Hindu majority. He was instrumental in establishing Hindu Line within the Congress.
In the 1952 general elections to the Parliament of India, Mookerjee and the BJS won 3 seats.
Sri Mookerjee was the one, who opposed Congress’s decision to allow Kashmir to be a special state and have its own Flag, Prime minister. according to congress’s decision, No One including the President of India can enter into Kashmir with out Kashmir’s prime minister.
In order to oppose this decision, he once said Ek desh mein do Vidhan, do Prdhan and Do Nishan nahi chalenge’ (A single contury can’t have two constitutions, two prime minister, and two National Emblem)
Mookerjee went to visit Kashmir in 1953, and went on hunger strike to protest the law prohibiting Indian citizens from settling in a state in their own country and the need to carry ID cards, and was arrested on 11th May while crossing border. Although the ID card rule was revoked owing to his efforts, he died as detenu on May 23, 1953 under mysterious circumstances. His death in custody raised wide suspicion across the country and demands for independent enquiry, including earnest requests from his mother, Jogmaya Devi to the then Prime Minister of India, Jawaharlal Nehru. Unfortunately no enquiry commission was set up and his death remains a mystery.
Along with Vinayak Damodar Savarkar, Mookerjee is considered the godfather of Hindu nationalism in India, especially the Hindutva movement. He is widely revered by members and supporters of the Rashtriya Swayamsevak Sangh and the Vishwa Hindu Parishad.
Mookerjee was a major role model to Atal Bihari Vajpayee, who made the BJS the chief Hindu conservative political party in the 1960s and 1970s, and founded its successor, the Bharatiya Janata Party. The BJP has become one of the two largest national political parties, the other being the Indian National Congress Party, and had formed the Government from 1998 to 2004, with Vajpayee serving as the Prime Minister of India.
On August 27, 1998, the Ahmedabad Municipal Corporation (governed by the BJP) named a bridge after Mookerjee.
In 2001, the main research funding institute of the Government of India , CSIR instituted a new fellowship named after him. The Shyama Prasad Mukhejee Fellowship is the most prestigious fellowship given in India for doing PhD.Only the top 20% students who clear the Junior Research Fellowship (JRF CSIR/UGC) are eligible to sit for this examination.