A jury trial, or trial by jury, is a lawful proceeding in which a jury makes a decision or findings of fact. It is distinguished from a bench trial in which a judge or panel of judges makes all decisions.

Jury trials are used in a significant share of serious criminal cases in many but not all common law judicial systems. The majority of common law jurisdictions in Asia (such as Singapore, Pakistan, India, and Malaysia) have abolished jury trials on the grounds that juries are susceptible to bias. Juries or lay judges have also been incorporated into the legal systems of many civil law countries for criminal cases. Only the United States makes routine use of jury trials in a wide variety of non-criminal cases. Other common law legal jurisdictions use jury trials only in a very select class of cases that make up a tiny share of the overall civil docket (like malicious prosecution and false imprisonment suits in England and Wales), but true civil jury trials are almost entirely absent elsewhere in the world. Some civil law jurisdictions, however, have arbitration panels where non-legally trained members decide cases in select subject-matter areas relevant to the arbitration panel members' areas of expertise.

The use of jury trials, which evolved within common law systems rather than civil law systems, has had a profound impact on the nature of American civil procedure and criminal procedure rules, even if a bench trial is actually contemplated in a particular case. In general, the availability of a jury trial if properly demanded has given rise to a system in which fact finding is concentrated in a single trial rather than multiple hearings, and appellate review of trial court decisions is greatly limited. Jury trials are of far less importance (or of no importance) in countries that do not have a common law system.