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 Virginia, consolidation of lawsuits is governed by the Virginia Rules of Supreme Court, specifically Rule 3:13. This rule allows for consolidation when actions involving a common question of law or fact are pending before the court. The court may 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 to prevent inconsistent judgments. Additionally, federal courts have their own rules regarding consolidation, as outlined in Federal Rule of Civil Procedure 42(a), which similarly allows for consolidation when actions before the court involve common questions of law or fact. The decision to transfer cases from one court to another for consolidation purposes, whether within the state court system or between state and federal courts, may also be influenced by factors such as the convenience of parties and witnesses, and the interests of justice.