United States.

The availability of a trial by jury in American jurisdictions varies. Because the United States legal system separated from that of the English one at the time of the American Revolution, the types of proceedings that use juries depends on whether such cases were tried by jury under English common law at that time rather than the methods used in English courts now. For example, at the time, English "courts of law" tried cases of torts or private law for monetary damages using juries, but "courts of equity" that tried civil cases seeking an injunction or another form of non-monetary relief did not. As a result, this practice continues in American civil laws, but in modern English law, only criminal proceedings and some inquiries are likely to be heard by a jury.

A distinctive feature of jury trials in the United States is that verdicts in criminal cases must usually be unanimous.

Every person accused of a crime punishable by incarceration for more than six months has a constitutionally protected right to a trial by jury, which arises in federal court from Article Three of the United States Constitution, which states in part, "The Trial of all Crimes...shall be by Jury; and such Trial shall be held in the State where the said Crimes shall have been committed." The right was expanded with the Sixth Amendment to the United States Constitution, which states in part, "In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury of the state and district wherein the crime shall have been committed." Both provisions were made applicable to the states through the Fourteenth Amendment. Most states' constitutions also grant the right of trial by jury in lesser criminal matters, though most have abrogated that right in offenses punishable by fine only. The Supreme Court has ruled that if imprisonment is for six months or less, trial by jury is not required, meaning a state may choose whether or not to permit trial by jury in such cases. Under the Federal Rules of Criminal Procedure, if the defendant is entitled to a jury trial, he may waive his right to have a jury, but both the government (prosecution) and court must consent to the waiver. Several states require jury trials for all crimes, "petty" or not.

In the cases Apprendi v New Jersey, (2000), and Blakely v Washington, (2004), the Supreme Court of the United States held that a criminal defendant has a right to a jury trial not only on the question of guilt or innocence, but any fact used to increase the defendant's sentence beyond the maximum otherwise allowed by statutes or sentencing guidelines. This invalidated the procedure in many states and the federal courts that allowed sentencing enhancement based on "a preponderance of evidence", where enhancement could be based on the judge's findings alone. Depending upon the state, a jury must be unanimous for either a guilty or not guilty decision. A hung jury results in the defendant's release, however charges against the defendant are not dropped and can be reinstated if the state so chooses.

Jurors in some states are selected through voter registration and drivers' license lists. A form is sent to prospective jurors to pre-qualify them by asking the recipient to answer questions about citizenship, disabilities, ability to understand the English language, and whether they have any conditions that would excuse them from being a juror. If they are deemed qualified, a summons is issued.