The justice of the peace is the small claims court in the judicial system of Belgium, and stands at the bottom of the Belgian judicial hierarchy. There is a justice of the peace for each judicial canton, which is the smallest geographical subdivision of Belgium for judicial purposes. Most judicial cantons cover multiple municipalities, except in the case of larger towns and cities, which are often divided into multiple judicial cantons. A judicial canton has an average population of 50,000 to 60,000 people, but some have a population as low as 30,000 people or as high as 100,000 people. The justices of the peace only have jurisdiction over their own canton. As of 2017, there are 187 cantons with as many justices of the peace in Belgium, who hear cases in 229 seats.

The tribunals of first instance are the main trial courts in the judicial system of Belgium. The tribunals of first instance are courts of general jurisdiction; in the sense that they have original jurisdiction over all types of cases not explicitly attributed to other courts. They handle a wide range of civil cases, criminal cases, and cases under the scope of juvenile law and family law. They also hear appeals against the judgements of the police tribunals and justices of the peace. The judgements of the tribunals of first instance can be appealed to the courts of appeal in turn. There is a tribunal of first instance for each of the twelve judicial arrondissements ("districts") of Belgium, except for the arrondissement of Brussels. The arrondissement of Brussels has two tribunals of first instance, a Dutch-speaking one and a French-speaking one, due to the sensitive linguistical situation in the area. The territories of the current judicial arrondissements largely coincide with those of the provinces of Belgium. Most of the tribunals of first instance have multiple geographical divisions, with each having their own seat. As of 2020, the 13 tribunals of first instance have 27 seats in total. Further below, an overview is provided of all seats of the tribunals of first instance per arrondissement.