Causes of action in civil litigation are specific claims provided by law that serve as the basis for parties to a lawsuit to recover money or property from each other—or to provide other legal or equitable relief, such as a court order requiring or prohibiting some act (injunctive relief). Examples of causes of action include breach of contract, fraud, breach of fiduciary duty, and negligence. Causes of action (also called claims) are usually located in a state or federal statute, or in court opinions (common law).

In Oklahoma, causes of action in civil litigation are the legal grounds on which a plaintiff bases their lawsuit to seek remedies such as monetary compensation, restitution, or injunctive relief. Common causes of action include breach of contract, where one party fails to fulfill the terms of a contract; fraud, involving intentional deception for personal gain; breach of fiduciary duty, where an individual fails to act in the best interest of another whom they owe a duty to; and negligence, where harm results from a party's failure to exercise reasonable care. These claims can be based on Oklahoma state statutes, such as the Oklahoma Uniform Commercial Code for breach of contract, or on common law principles derived from judicial opinions. Additionally, federal laws may provide the basis for certain causes of action, such as those involving federal regulations or interstate matters. An attorney can help identify the appropriate cause of action and the legal basis for pursuing a claim in Oklahoma courts.