Nunez v. Dautel was a United States Supreme Court case that addressed the issue of whether a state court could enforce a contract that was made in violation of a federal statute. The case involved a contract between two individuals, Nunez and Dautel, in which Nunez agreed to pay Dautel a certain amount of money for the purchase of a piece of land. The contract was made in violation of a federal statute that prohibited the sale of land to non-citizens. The Supreme Court held that the state court could not enforce the contract because it was in violation of a federal statute. The Court reasoned that the federal statute was a valid exercise of Congress' power to regulate commerce and that the state court could not enforce a contract that was in violation of a federal law. The Court also noted that the contract was void ab initio, meaning that it was void from the beginning and could not be enforced by any court. The Court's decision in Nunez v. Dautel established that state courts must abide by federal statutes and cannot enforce contracts that are in violation of federal law. This decision has been cited in numerous cases since then and has been used to support the principle that state courts must follow federal law.

Justice Field delivered the dissenting opinion in Nunez v. Dautel, arguing that the majority's decision was wrongfully based on a misreading of California law. He argued that under California law, an action for damages could be brought against a party who had fraudulently obtained title to real property from another person. The majority held that such an action could not be maintained because it would amount to a collateral attack on the judgment of registration which vested title in Dautel; however, Justice Field disagreed and noted that this case did not involve any question as to whether or not there had been fraud practiced upon the court issuing its decree but rather involved only questions between two private parties concerning their respective rights with respect to certain land. Furthermore, he asserted that even if there were some doubt as to whether or not such an action was maintainable under California law at common law, then certainly it should have been allowed by virtue of section 1260 of the Code Civil Procedure which provided for actions "for relief on account of any injury done contrary thereto." Thus Justice Field concluded his dissent by stating: "The conclusion reached by my brethren is therefore erroneous and I am constrained accordingly to dissent from it."