Dean Witter Reynolds Inc. v. Byrd, 470 U.S. 213 (1985), is a United States Supreme Court case concerning arbitration. It arose from an interlocutory appeal of a lower court's denial of brokerage firm Dean Witter Reynolds' motion to compel arbitration of the claims under state law made against it by an aggrieved former client. The Court held unanimously that the Federal Arbitration Act required that those claims be heard that way when the parties were contractually obligated to do so, even where parallel claims made under federal law would still be heard in federal court.