The British and Irish Legal Information Institute or BAILII is a free legal information research database covering case law, legislation and other materials from the jurisdictions of the United Kingdom, England & Wales, Scotland, Northern Ireland, plus Ireland, the Channel Islands, the European Court of Justice, the European Court of Human Rights.

Incorporated and established as a charity in December 2000, BAILII is based at the Institute of Advanced Legal Studies and is a member of the Free Access to Law movement.