United States v. Weld is a United States Supreme Court case that was decided in 1887. The case involved a dispute between the United States and the heirs of William Weld, a former owner of a wharf in Boston, Massachusetts. The United States had taken possession of the wharf in 1871 for use as a naval station. The Weld heirs argued that the taking of the wharf was unconstitutional because it was done without just compensation. The Supreme Court held that the taking of the wharf was constitutional because it was done for a public purpose. The Court noted that the United States had the power to take private property for public use, provided that just compensation was paid. The Court also held that the taking of the wharf was not a violation of the Fifth Amendment because the Weld heirs had not been deprived of their property without due process of law. The Court concluded that the taking of the wharf was constitutional and that the Weld heirs were entitled to just compensation for the taking. The Court ordered the United States to pay the Weld heirs the fair market value of the wharf at the time of the taking.

In United States v. Weld, the Supreme Court was tasked with determining whether a federal court had jurisdiction to hear an appeal from a decision of the Massachusetts Circuit Court in admiralty cases. The majority opinion held that it did not have such jurisdiction, as Congress had not granted it authority to do so. Justice Field dissented from this ruling and argued that Congress had intended for appeals in admiralty cases to be heard by the federal courts when they were brought up on writs of error or appeal under section 563 of the Revised Statutes. He noted that while there may have been some ambiguity regarding congressional intent, he believed that allowing appeals would further justice and promote uniformity among all states' laws concerning maritime matters. Furthermore, he argued against interpreting statutes too narrowly since doing so could lead to injustice if certain rights are denied due solely to technicalities rather than substance.