Gaines v. Fuentes et al. was a United States Supreme Court case that dealt with the issue of due process. The case involved a dispute between a man named Gaines and a married couple, the Fuentes. Gaines had purchased a piece of land from the Fuentes, but the Fuentes later attempted to reclaim the land. Gaines argued that he had not been given due process in the matter, as he had not been given notice of the Fuentes' intent to reclaim the land. The Supreme Court ultimately ruled in favor of Gaines, finding that the Fuentes had violated his right to due process. The Court held that the Fuentes had not given Gaines proper notice of their intent to reclaim the land, and that this constituted a violation of his right to due process. The Court also held that the Fuentes had not provided Gaines with an opportunity to be heard in the matter, which was also a violation of his right to due process. The Court's ruling in Gaines v. Fuentes et al. established that individuals have a right to due process when their property is at stake. This ruling has been cited in numerous subsequent cases, and has been used to protect the rights of individuals in a variety of contexts.

In Gaines v. Fuentes et al., the Supreme Court was asked to decide whether a state law that required African Americans to attend separate schools from white students violated the Equal Protection Clause of the Fourteenth Amendment. The majority held that it did not, but Justice Harlan dissented and argued that this law created an unconstitutional racial classification in violation of equal protection principles. He reasoned that since all citizens are entitled to equal protection under the Constitution, any laws which create distinctions based on race should be subject to strict scrutiny by courts and must serve a compelling governmental interest in order for them to be upheld as constitutional. In this case, he found no such compelling justification for creating different educational facilities for black and white children; instead he believed it perpetuated inequality between races and thus could not pass constitutional muster.