The court of assizes is the trial court which tries the most serious crimes in the judicial system of Belgium. It is the highest Belgian court with criminal jurisdiction; as such, it is the only Belgian court that can sentence someone to life imprisonment. The courts of assizes are not permanent courts; a new court of assizes is assembled for each new trial. There is a court of assizes in each of the ten provinces of Belgium, as well as one in the arrondissement of Brussels-Capital which is not part of any province. Further below, an overview is provided of the eleven courts of assizes and their seats. They are the only courts in Belgium for which the provinces are used as territorial subdivisions. They are also the only courts in Belgium that hold jury trials. The jury acts as sole trier of fact, but decides on the penalty together with the judges. The trial by jury of certain crimes is laid down in article 150 of the Belgian Constitution. The Belgian courts of assizes have the same origin as their French namesakes.

A jury trial, or trial by jury, is a legal 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.