Oyama v. State of California, 332 U.S. 633 (1948) was a United States Supreme Court decision that ruled that specific provisions of the 1913 and 1920 California Alien Land Laws abridged the rights and privileges guaranteed by the Fourteenth Amendment to Fred Oyama, a U.S. citizen in whose name his father, a Japanese citizen, had purchased land.

This was in part to appease the nervous California farmers, who feared that the Japanese immigrants' agricultural techniques, which developed out of the necessity to make as much use of small plots of land as possible, would render them unable to compete economically.

A commonly used way to get around it was to purchase land in the name of their US-born children (who, by birth, were automatically granted American citizenship) and then to become the guardian of the property.

In response to those tactics, the 1920 version of the California Alien Land Law included more stringent rules designed to end such circumvention.

World War II tensions contributed significantly to the development of those issues, as anti-Japanese sentiments grew more heated and the internment of Japanese persons took place.

It further ruled that California was permitted to exclude ineligible aliens from purchasing, transferring, and owning agricultural land and that Fred Oyama was deprived of no constitutional guarantees.

Chief Justice Vinson, delivering the opinion of the Court, wrote strictly on the facts of the case, without giving much note to its broader implications.

While freely admitting that it is apparent that the enforcement of the Alien Land Laws in that case resulted in abridgement of equal protection afforded to Fred Oyama by his status as an American citizen, the Supreme Court's opinion rendered by Vinson did not go so far as to rule on or, in fact, even address the constitutionality of the statute.

Invalidating the California Alien Land Law would have required overturning the precedents of those decisions, something that the Court is typically loath to do, especially so shortly after the earlier cases.

In this case, the Court was able to address the unfairness of the application of the law by focusing on the petitioners first contention and effectively ignore the broader implications.

Justice Reed stated that he disagreed with the Court's opinion that the Alien Land Laws of California discriminated against Fred Oyama, an American citizen.

Associate Justice Jackson wrote in his dissenting opinion that since the Court upheld the Alien Land Law, it could not logically set aside the judgment that resulted from its valid enforcement.