Legal research is the process of identifying, analysing and applying relevant legal sources to answer a specific legal question or solve a client problem. In practice, this includes locating and interpreting primary sources (legislation, statutory instruments, case law and constitutional provisions), as well as secondary sources (textbooks, commentary, practitioner texts and journal articles). The expression “legal research” is descriptive rather than formally defined in UK or Irish legislation or case law, but it underpins competent legal advice, advocacy, drafting and risk management across all practice areas. Legal research typically involves: developing research questions; using legal research platforms, law reports and official publications; checking legislative history and amendments; distinguishing and reconciling authorities; and assessing the weight and hierarchy of sources (including persuasive versus binding precedent). Across England and Wales, Scotland, Northern Ireland and Ireland, the core concept and professional expectations are broadly consistent, though the relevant courts, legislative instruments and citation practices differ between jurisdictions. Sound legal research is a key component of professional competence and ethical practice, and is essential for due diligence, opinion writing, litigation strategy and transactional work.