Williams v. Ottawa is a United States Supreme Court case that was decided in 1881. The case involved a dispute between the City of Ottawa, Illinois and the plaintiff, John Williams. Williams had been hired by the City of Ottawa to construct a bridge over the Fox River. The City had agreed to pay Williams for his work, but failed to do so. Williams then sued the City for breach of contract. The Supreme Court held that the City of Ottawa was liable for breach of contract. The Court found that the City had entered into a valid contract with Williams and had failed to fulfill its obligations under the contract. The Court also held that the City was liable for damages, as Williams had suffered a loss due to the City's breach of contract. The Court's decision in Williams v. Ottawa established that a municipality can be held liable for breach of contract. This decision has been cited in numerous subsequent cases involving municipal contracts. The decision also serves as an important reminder that municipalities must fulfill their contractual obligations in order to avoid liability.

In Williams v. Nottawa, the Supreme Court was asked to decide whether a Native American woman who had married a white man could be considered an Indian for purposes of determining her right to land in Michigan. The majority opinion held that she did not qualify as an Indian and thus lacked standing to bring suit against the United States government for title to the land. In dissent, Justice Field argued that Congress had intended for all Indians living on reservations at the time of their creation—regardless of race or marital status—to have equal rights with respect to lands within those reservations. He further noted that Congress had never explicitly excluded mixed-race individuals from its definition of “Indian” and therefore it should be assumed they were included unless otherwise stated by law. As such, he concluded that Nottawa should have been allowed access to her husband's allotment under federal law and given standing in court proceedings related thereto.