Fleming v. Soutter was a United States Supreme Court case that dealt with the issue of whether a state court had the authority to issue a writ of habeas corpus to a prisoner held in a federal prison. The case arose when a prisoner, John Fleming, was held in a federal prison in the District of Columbia. He sought a writ of habeas corpus from the Supreme Court of the District of Columbia, which was denied. Fleming then appealed to the Supreme Court of the United States. The Supreme Court held that the state court did not have the authority to issue a writ of habeas corpus to a prisoner held in a federal prison. The Court reasoned that the power to issue a writ of habeas corpus was a federal power, and that the state court did not have the authority to interfere with the federal government's power to imprison individuals. The Court also noted that the writ of habeas corpus was a fundamental right, and that the federal government had the exclusive power to protect that right. The Court's decision in Fleming v. Soutter established that the federal government had exclusive authority to issue writs of habeas corpus to prisoners held in federal prisons. This decision has been cited in numerous subsequent cases, and has been used to support the idea that the federal government has exclusive authority over matters related to the imprisonment of individuals.

In Fleming v. Soutter, the Supreme Court was asked to decide whether a contract between two parties could be enforced when one of them had died before it was fully executed. The majority opinion held that the contract could not be enforced because it had not been completed by both parties prior to death and thus did not meet all of the requirements for a valid agreement under state law. Justice Field dissented from this decision, arguing that while contracts must generally be performed in order for them to be enforceable, there are exceptions where performance is impossible due to circumstances beyond either party's control such as death or illness. In this case, he argued that since only one party remained alive at the time of judgment and they were unable to complete their part of the agreement due to no fault on their own part, then justice should dictate that they still receive some compensation for what would have been done if both parties were able to fulfill their obligations under the contract.