Chakravarti Rajagopalachari BR (10 December 1878 – 25 December 1972), popularly known as Rajaji or C.R., also known as Mootharignar Rajaji (Rajaji, the Scholar Emeritus), was an Indian statesman, writer, lawyer, and independence activist. Rajagopalachari was the last Governor-General of India, as India became a republic in 1950. He was also the first Indian-born Governor-General, as all previous holders of the post were British nationals. He also served as leader of the Indian National Congress, Premier of the Madras Presidency, Governor of West Bengal, Minister for Home Affairs of the Indian Union and Chief Minister of Madras state. Rajagopalachari founded the Swatantra Party and was one of the first recipients of India's highest civilian award, the Bharat Ratna. He vehemently opposed the use of nuclear weapons and was a proponent of world peace and disarmament. During his lifetime, he also acquired the nickname 'Mango of Salem'.

Rajagopalachari was born in the Thorapalli village of Hosur taluk in the Krishnagiri district of Tamil Nadu and was educated at Central College, Bangalore, and Presidency College, Madras. In the 1900s he started legal practice at the Salem court. On entering politics, he became a member and later Chairperson of the Salem municipality. One of Mahatma Gandhi's earliest political lieutenants, he joined the Indian National Congress and participated in the agitations against the Rowlatt Act, joining the Non-Cooperation movement, the Vaikom Satyagraha, and the Civil Disobedience movement. In 1930, Rajagopalachari risked imprisonment when he led the Vedaranyam Salt Satyagraha in response to the Dandi March. In 1937, Rajagopalachari was elected Prime minister of the Madras Presidency and served until 1940, when he resigned due to Britain's declaration of war on Germany. He later advocated co-operation over Britain's war effort and opposed the Quit India Movement. He favoured talks with both Muhammad Ali Jinnah and the Muslim League and proposed what later came to be known as the C. R. formula. In 1946, Rajagopalachari was appointed Minister of Industry, Supply, Education and Finance in the Interim Government of India, and then as the Governor of West Bengal from 1947 to 1948, Governor-General of India from 1948 to 1950, Union Home Minister from 1951 to 1952 and as Chief Minister of Madras state from 1952 to 1954. In 1959, he resigned from the Indian National Congress and founded the Swatantra Party, which fought against the Congress in the 1962, 1967 and 1971 elections. Rajagopalachari was instrumental in setting up a united Anti-Congress front in Madras state under C. N. Annadurai, which swept the 1967 elections. He died on 25 December 1972 at the age of 94 and received a state funeral.

Rajagopalachari was an accomplished writer who made lasting contributions to Indian English literature and is also credited with the composition of the song Kurai Onrum Illai set to Carnatic music. He pioneered temperance and temple entry movements in India and advocated Dalit upliftment. He has been criticized for introducing the compulsory study of Hindi and the Madras Scheme of Elementary Education in Madras State, dubbed by its critics as Hereditary Education Policy put forward to perpetuate caste hierarchy. Critics have often attributed his pre-eminence in politics to his standing as a favourite of both Mahatma Gandhi and Jawaharlal Nehru. Rajagopalachari was described by Gandhi as the "keeper of my conscience".