A dispositive fact is a fact which, if accepted, decides a claim, defence or discrete issue, allowing the court or tribunal to dispose of the case or issue without needing to determine anything further. It is a descriptive expression rather than a defined term in UK or Irish legislation, though courts and practitioners use it alongside “determinative”, “issue‑determinative” or “material” fact.Dispositive facts are typically the “ultimate” facts in issue: for example, in negligence, the absence of a duty of care; on limitation, that the claim is time‑barred; in contract, that no contract was formed. They can be established by evidence, formal admissions or agreed facts, and align with the party’s legal burden of proof: a claimant must prove the dispositive facts of the cause of action; a defendant the dispositive facts of any affirmative defence.Identifying dispositive facts drives case strategy, pleadings, disclosure, and witness statements, and underpins applications for summary judgment or strike‑out (including summary decree in Scotland), or for determination of a preliminary issue. Usage and effect are broadly consistent across England and Wales, Scotland, Northern Ireland and Ireland, although local procedural labels differ.