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 Illinois, a motion to dismiss is governed by the Illinois Code of Civil Procedure, specifically under Section 2-615 and Section 2-619. A Section 2-615 motion challenges the legal sufficiency of the complaint, asserting that even if all the facts alleged are true, there is no legal basis for a lawsuit. This includes grounds such as failure to state a claim upon which relief can be granted. A Section 2-619 motion allows for dismissal based on certain defects or defenses, such as lack of jurisdiction, statute of limitations, and other affirmative matters that avoid the legal effect of or defeat a claim. These motions must be filed before any other pleadings, and they are typically filed early in the litigation process. If the court grants a motion to dismiss, the case may be terminated without a trial on the merits, although in some instances, plaintiffs may be given an opportunity to amend their complaint to address the issues raised in the motion.