The Prime Minister of India is, in practice, the most powerful person in the Government of India. The Prime Minister is technically outranked by the head of state, the President of India. But, as is typical in most parliamentary democracies, because the head of state's duties are largely ceremonial, the Prime Minister is the head of government and has effective responsibility for executive power.

India follows a parliamentary system of government, known as the Westminster system after that of the United Kingdom. In this system, the Prime Minister is generally the leader of a party (or coalition of parties) that has a majority in the Lok Sabha, the lower house of the Parliament of India. The Prime Minister either has to be a current member of one of the houses of Parliament, or be elected within six months of being appointed.