Ajay Hasia v Khalid Mujib, (1981) 1 SCC 722, was a landmark decision by the Supreme Court of India in which the Court laid down a test to determine whether an individual, corporation, or society was an instrumentality or agency of the government, and therefore whether it could be considered a State for the purposes of Article 12 of the Constitution of India.

[1] If a body is 'State' for the purposes of Article 12, a writ can lie against them for violating the Constitution.

[1]: 29  The judgment of the Court, delivered by Justice P. N. Bhagwati, was largely a summarization of Bhagwati's view in R. D. Shetty v International Airport Authority of India.

Ajay Hasia summarized International Airport Authority into a six-factor test to determine whether a body was an instrumentality of agency of the State.

[1]: 29  The most influential portion of the judgment is the summarized six-factor test and largely the reason why it is often cited over the International Airport Authority case, a previous judgment by Justice Bhagwati.