Hunnicutt v. Peyton was a United States Supreme Court case that dealt with the issue of whether a state court had the authority to issue a writ of mandamus to a county court. The case arose when the plaintiff, William Hunnicutt, sought to compel the defendant, William Peyton, to issue a writ of mandamus to the county court of Montgomery County, Virginia. The plaintiff argued that the county court had failed to issue a writ of mandamus to the defendant, despite the fact that the plaintiff had requested it. The Supreme Court held that the state court did not have the authority to issue a writ of mandamus to the county court. The Court reasoned that the writ of mandamus was a writ of right, and that the state court did not have the power to issue such a writ. The Court further held that the writ of mandamus was a writ of right, and that the state court did not have the power to issue such a writ. The Court's decision in Hunnicutt v. Peyton established that state courts do not have the authority to issue writs of mandamus to county courts. This decision has been cited in numerous subsequent cases, and has been used to support the principle that state courts do not have the power to issue writs of mandamus to county courts.

In Hunnicutt v. Peyton, the Supreme Court was asked to decide whether a Virginia statute that allowed for the sale of land belonging to an estate in order to pay off debts was constitutional. The majority opinion held that it was not unconstitutional and upheld the validity of the statute. However, Justice Field dissented from this decision on two grounds: first, he argued that there were no provisions in either state or federal law allowing for such sales; second, he contended that if such sales were permitted they would be contrary to public policy as they would allow creditors to take advantage of debtors who had already been deprived of their property through death or other misfortune. He concluded by noting his belief that any attempt by states to pass laws authorizing these types of sales should be declared void as being against public policy and beyond their power under both state and federal constitutions.