Consolidation of lawsuits may be ordered by a court when two or more lawsuits involving the same or similar parties (plaintiff and defendant), legal issues, and factual issues are pending in the same court or in different courts in the same jurisdiction (state court system or federal court system). If the lawsuits are pending in different courts one case may be transferred to the other court, and the cases consolidated there.

Laws and rules regarding the consolidation—or transfer and consolidation—of lawsuits vary from state to state and in the federal court system.

In Minnesota, the consolidation of lawsuits is governed by the Minnesota Rules of Civil Procedure, specifically Rule 42.01, which allows for consolidation when actions involving a common question of law or fact are pending before the court. This rule permits a court to order a joint hearing or trial of any or all the matters in issue in the actions, consolidate the actions, or issue any other orders to avoid unnecessary costs or delay. The decision to consolidate is at the discretion of the court and is typically done to promote efficiency and consistency in the handling of similar cases. Additionally, federal courts have a similar provision under Rule 42 of the Federal Rules of Civil Procedure, which allows for consolidation when cases involve common questions of law or fact. The decision to transfer cases from one federal district court to another for consolidation purposes can be made under 28 U.S.C. § 1404(a), which allows for the transfer of a case for the convenience of parties and witnesses and in the interest of justice.