A controversy is an actual dispute, which refers to one of the underlying requirements to obtain jurisdiction in federal court. U.S Constitution, Article III, section 2, in setting out the powers of the Federal judiciary, grants federal courts the power to hear both certain “cases” and certain “controversies.”
In framing judicial authority these words also represent limits. For example, the federal courts do not, under Article III, have the power to resolve legal questions that do not arise out of an actual dispute between real parties because no controversy exists. This limit on hearing collusive suits is known as the ban on issuing advisory opinions.
Furthermore, controversies must be ripe, or in current existence, to warrant judicial intervention. In Renne v. Geary for example, the court found no controversy because the plaintiff cited actions that the defendant expressed interest in taking, not action the defendant already took/were in the process of taking.
In some states, the highest courts have jurisdiction to hear and provide advisory opinions on questions submitted by the state legislature. In these situations, a controversy is not required for a court to obtain jurisdiction. Nonetheless, a statute attempting to give such jurisdiction to the federal courts would run into the constitutionally based requirement of a "case" or "controversy.”
[Last updated in July of 2022 by the Wex Definitions Team]