A motion to dismiss is a formal request (usually in a written motion) asking the court to dismiss a lawsuit or case for one of the reasons described in the relevant state or federal rule of civil procedure.

A motion to dismiss is usually filed in the early stages of the litigation and may be required before the party files any other pleading. Some of the common bases on which a case may be dismissed by the court include: (1) statute of limitations expired; (2) lack of subject-matter jurisdiction; (3) lack of personal jurisdiction; (4) improper venue; (5) insufficient process; (6) insufficient service of process; (7) failure to state a claim upon which relief can be granted; and (8) failure to join a party.

In Missouri, a motion to dismiss is governed by the Missouri Rules of Civil Procedure, particularly Rule 55.27. This rule outlines the various grounds upon which a party can request the court to dismiss a case. These grounds include the expiration of the statute of limitations, lack of subject-matter jurisdiction, lack of personal jurisdiction, improper venue, insufficient process, insufficient service of process, failure to state a claim upon which relief can be granted, and failure to join a necessary party. The motion to dismiss is typically filed by the defendant after being served with the plaintiff's complaint but before filing an answer or other responsive pleading. If the court grants the motion, the case is dismissed and terminated without further consideration. However, depending on the specific grounds for dismissal, some dismissals may be without prejudice, allowing the plaintiff to correct the issue and refile the case.