Employees in three consolidated cases signed employment agreements requiring individualized arbitration of disputes. They later sought to pursue wage-and-hour claims through class or collective actions, arguing that the Federal Arbitration Act’s saving clause and the National Labor Relations Act protected concerted litigation. The Supreme Court held that the arbitration agreements must be enforced as written. The Federal Arbitration Act recognizes generally applicable contract defenses but does not permit a defense aimed at arbitration’s fundamental attributes, such as individualized proceedings. The National Labor Relations Act’s protection for employees’ concerted activities does not clearly displace the Arbitration Act or create a right to class or collective litigation in court or arbitration. The Court emphasized that Congress knows how to override the Arbitration Act when it intends to do so and had not done so in the National Labor Relations Act. It reversed the lower-court judgments and upheld enforcement of the individualized arbitration agreements. Justice Ginsburg, joined in relevant part by other Justices, dissented and warned that the decision would undermine workers’ ability to pursue workplace claims collectively.