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 Tennessee, consolidation of lawsuits is governed by the Tennessee Rules of Civil Procedure, specifically Rule 42.02, which allows for consolidation when actions involving a common question of law or fact are pending before the court. This is to promote efficiency and avoid inconsistent judgments. The court has the discretion to order a joint hearing or trial of any or all the matters in question in the actions, or it may order all the actions consolidated, and it may make such orders concerning proceedings therein as may tend to avoid unnecessary costs or delay. Additionally, if cases are in different courts but within the same jurisdiction, a transfer may be requested to consolidate the cases in one court. The decision to consolidate is at the discretion of the court and is based on the aim to reduce prejudice, inconvenience, or expense to the parties. Federal courts follow a similar rationale under the Federal Rules of Civil Procedure, Rule 42(a), which also allows for consolidation of cases that involve common questions of law or fact to streamline the process and reduce the risk of inconsistent rulings.