Under Illinois law, marital settlement agreements are highly favored and will generally be enforced by the courts.
The text of 70 ILCS 5/501 is set forth, in full, below:
§ 502. Agreement. (a) To promote amicable settlement of disputes between parties to a marriage attendant upon the dissolution of their marriage, the parties may enter into a written or oral agreement containing provisions for disposition of any property owned by either of them, maintenance of either of them and support, custody and visitation of their children.
(b) The terms of the agreement, except those providing for the support, custody and visitation of children, are binding upon the court unless it finds, after considering the economic circumstances of the parties and any other relevant evidence produced by the parties, on their own motion or on request of the court, that the agreement is unconscionable.
(c) If the court finds the agreement unconscionable, it may request the parties to submit a revised agreement or upon hearing, may make orders for the disposition of property, maintenance, child support and other matters.
(d) Unless the agreement provides to the contrary, its terms shall be set forth in the judgment, and the parties shall be ordered to perform under such terms, or if the agreement provides that its terms shall not be set forth in the judgment, the judgment shall identify the agreement and state that the court has approved its terms.
(e) Terms of the agreement set forth in the judgment are enforceable by all remedies available for enforcement of a judgment, including contempt, and are enforceable as contract terms.
(f) Except for terms concerning the support, custody or visitation of children, the judgment may expressly preclude or limit modification of terms set forth in the judgment if the agreement so provides. Otherwise, terms of an agreement set forth in the judgment are automatically modified by modification of the judgment.