Ober v. Gallagher 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 state statute. The case involved a contract between two parties, Ober and Gallagher, in which Ober agreed to pay Gallagher a certain amount of money in exchange for Gallagher's services. The contract was made in violation of a state statute that prohibited such contracts. The Supreme Court held that the state court could not enforce the contract because it was made in violation of the state statute. The Court reasoned that the state statute was a valid exercise of the state's police power and that the state had the right to protect its citizens from contracts that were made in violation of the law. The Court also noted that the state had the right to protect its citizens from contracts that were made without consideration or that were otherwise unfair. The Court's decision in Ober v. Gallagher established that state courts could not enforce contracts that were made in violation of state statutes. This decision has been cited in numerous cases since then and has been used to support the idea that state courts should not enforce contracts that are made in violation of state law.

In Ober v. Gallagher, the United States Supreme Court was tasked with determining whether a state court had jurisdiction to hear a case involving an alleged breach of contract between two citizens from different states. The majority opinion held that the state court did not have jurisdiction in this matter because it involved parties from different states and thus fell under federal law. Justice Field dissented, arguing that while there may be some cases where federal law applies, this particular dispute should still fall within the purview of state courts as it involves only private individuals and does not involve any questions of public policy or national interests. He further argued that allowing such disputes to be heard by state courts would promote uniformity among all jurisdictions and prevent unnecessary delays in resolving these matters due to jurisdictional issues.