Hopt v. Utah was a United States Supreme Court case that addressed the issue of whether a state could impose criminal penalties for the refusal to answer questions posed by a grand jury. The case arose when a grand jury in Utah issued a subpoena to a witness, who refused to answer certain questions on the grounds that they were irrelevant to the investigation. The witness was then charged with contempt of court and sentenced to jail. The Supreme Court held that the state of Utah had violated the witness's Fifth Amendment right against self-incrimination. The Court reasoned that the witness had a right to remain silent and that the state could not punish him for exercising that right. The Court also noted that the state had failed to provide the witness with any protection against self-incrimination, such as immunity from prosecution. The decision in Hopt v. Utah established that a state cannot punish a witness for refusing to answer questions posed by a grand jury. The decision also established that a witness must be provided with some form of protection against self-incrimination, such as immunity from prosecution, before they can be compelled to answer questions. This decision has been cited in numerous subsequent cases involving the Fifth Amendment right against self-incrimination.

Justice Field delivered the dissenting opinion in Hopt v. Utah, arguing that the majority's decision was a violation of due process and an unjustified extension of state power. He argued that while states have broad authority to regulate certain activities within their borders, they cannot use this power to violate fundamental rights guaranteed by the Constitution. In this case, he believed that Utah had gone too far in its attempt to criminalize polygamy and infringe upon individuals' right to practice their religion freely without government interference. Furthermore, Justice Field noted that even if polygamy were considered immoral or socially undesirable it did not necessarily follow that it should be prohibited by law; instead he suggested allowing public opinion and social pressure work against such practices rather than relying on coercive legislation from the state government.