Ijmāʿ (Arabic, إجماع) refers to the consensus of the ummah, the community of Muslims, those practicing Islam, or of the ulema, those learned in the relevant topic. Islamic law prescribes specific means of consensus decision making which Muslims are to follow in making and enforcing law.

The hadith "My community will never agree upon an error" is often cited as support for the validity of ijma.

Sunni Muslims regard ijma as the fourth fundamental source of law, after Qur'an, Sunnah, and qiyas (analogy).

See also: Five Pillars of Islam, deliberative democracy, ijtihad