A mass tort is a civil lawsuit that involves hundreds or thousands of plaintiffs and one or a few defendants in which the plaintiffs have the same or similar claims against the defendant or defendants. Mass tort lawsuits are often filed as class action lawsuits (a procedural mechanism for joining the plaintiffs in one lawsuit), and are typically based on alleged wrongful acts (torts) such as exposure of the plaintiffs to harmful substances (asbestos or benzene), or defective products (pharmaceuticals or medical devices), or invasions of privacy (data breaches).

In Oklahoma, a mass tort is a type of legal action where a large number of plaintiffs bring a claim against one or a few defendants for similar or related injuries. These cases often arise from exposure to harmful substances, defective products, or invasions of privacy such as data breaches. While mass torts can be filed individually, they are frequently handled as class action lawsuits, which allows for the consolidation of many individual claims into a single action for efficiency and consistency. Oklahoma follows both state statutes and federal laws governing class actions and mass torts. Under the Federal Rules of Civil Procedure, specifically Rule 23, class actions must meet certain requirements such as commonality, adequacy, and typicality of the claims. Additionally, the Oklahoma Class Action Reform Act (OCARA) may also apply, which includes provisions to prevent abuse of class actions and to ensure that they are used appropriately. It's important to consult with an attorney to understand the specific legal standards and procedures that apply to mass torts in Oklahoma.