Article 81 of the Constitution of India is a fundamental constitutional provision that defines the Composition of the House of the People (Lok Sabha), the lower house of Parliament. It was part of the original Constitution adopted in 1950, with its draft debated on January 4, 1949, and October 17, 1949, to establish a structure that ensures representation based on population.
The provision currently mandates that the Lok Sabha shall consist of not more than 530 members chosen by direct election from the States, and not more than 20 members to represent the Union Territories. Article 81(2) establishes the core mechanism of proportional representation, requiring that the ratio between the number of seats allotted to a State and its population must be, as far as practicable, the same for all States. The term "population" is defined in Article 81(3) as the figures from the last preceding census.
Article 81 is intrinsically linked to the process of Delimitation under Article 82 and the reservation of seats for Scheduled Castes and Scheduled Tribes under Article 330 and Article 332. The maximum strength for States was increased from 500 to 525 by the Constitution (Thirty-First Amendment) Act, 1973. The most significant change is the freeze on seat allocation and constituency division, which was extended by the 84th Amendment Act, 2001, to remain based on the 1971 Census until the first census taken after the year 2026. Furthermore, the provision for the President to nominate two members of the Anglo-Indian community, which Article 81 was subject to via Article 331, was discontinued by the 104th Constitutional Amendment Act, 2020.