Indira Gandhi was an Indian politician who served as the third Prime Minister of India from 1966 to 1977 and again from 1980 until her assassination in 1984. She was India's first and, to date, only female prime minister, and a central figure in Indian politics as the leader of the Indian National Congress. Gandhi was the daughter of Jawaharlal Nehru, the first prime minister of India, and the mother of Rajiv Gandhi, who succeeded her in office as the country's sixth prime minister. Furthermore, Gandhi's cumulative tenure of 15 years and 350 days makes her the second-longest-serving Indian prime minister after her father. Henry Kissinger described her as an "Iron Lady", a nickname that became associated with her tough personality since her lifetime.

The prime minister of India is the head of government of the Republic of India. Executive authority is vested in the prime minister and his chosen Council of Ministers, despite the president of India being the nominal head of the executive. The prime minister has to be a member of one of the houses of bicameral Parliament of India, alongside heading the respective house. The prime minister and their cabinet are at all times responsible to the Lok Sabha.