Sir Benegal Narsing Rau CIE (26 February 1887 – 30 November 1953) was an Indian civil servant, jurist, diplomat and statesman known for his role as the Constitutional Advisor to Constituent Assembly.

He was India's representative to the United Nations Security Council from 1950 to 1952, and was serving as its president when it recommended armed assistance to South Korea in June 1950.

After revising the entire Indian statutory code (1935–37), he was knighted in 1938 and was made judge of the Bengal High Court at Calcutta in 1939.

His writings on Indian law include a noted study on constitutional precedents as well as articles on human rights in India.

B. N. Rau was born during the late British Raj on 26 February 1887 in a well-educated and prosperous Hindu Saraswat Brahmin family.

Rau graduated from the Canara High School, Mangalore (Ancient Tulunad Head quarters), topping the list of students of the entire Madras Presidency.

[7] B. N. Rau returned to British India after successfully passing the Indian Civil Service Examination in 1909, posted to Bengal.

[10] His distinguished work brought him a Companion of the Order of the Indian Empire (CIE) in the 1934 New Year Honours list[11] and a knighthood in 1938.

"[10] Following his resignation as Chief Minister of Kashmir, Rau was asked to serve in a temporary capacity in the Reforms Office of the Government of India, which he did so.

He was also offered, and declined, the position of a permanent judge on the Calcutta High Court, preferring to stay in the Reforms office and work on constitutional and federal issues.

[13] While the Constituent Assembly was engaged in discussing the draft Constitution, Rau also worked on preparing a brief on the question of whether the United Nations Security Council could intervene in a dispute between the Nizam of Hyderabad and the Indian government, and was part of a delegation that represented India at the United Nations General Assembly, concerning this question as well as issued relating to the peaceful uses of atomic energy.

[18] Amongst others, he met Justice Felix Frankfurter of the American Supreme Court, who famously advised him against the inclusion of a clause for 'due process' in the Indian Constitution as it would impose an 'undue burden' on the judiciary.

[23] Rau was invited by the Ministry of External Affairs to stand for election to the International Court of Justice towards the end of 1951, and began service towards 1952.

[25] The Prime Minister of India Jawaharlal Nehru spoke in Parliament about his death and the house paid tribute by observing a moment of silence.