Ex Parte Phoenix Insurance Company & Others is a United States Supreme Court case that was decided in 1886. The case involved a dispute between the Phoenix Insurance Company and the City of New York. The City of New York had passed a law that required all insurance companies doing business in the city to pay a certain amount of money to the city. The Phoenix Insurance Company argued that the law was unconstitutional because it violated the Due Process Clause of the Fourteenth Amendment. The Supreme Court agreed with the Phoenix Insurance Company and held that the law was unconstitutional. The Court reasoned that the law was an arbitrary exercise of power by the City of New York and that it violated the Due Process Clause of the Fourteenth Amendment. The Court also held that the law was not a valid exercise of the City's police power and that it was an unconstitutional taking of property without just compensation. The Court's decision in this case established the principle that the government cannot pass laws that are arbitrary and violate the Due Process Clause of the Fourteenth Amendment. This case is still cited today as an example of the importance of the Due Process Clause in protecting the rights of individuals and businesses.

In Ex Parte Phoenix Insurance Company & Others, the Supreme Court was asked to decide whether a state court had jurisdiction over an insurance company incorporated in another state. The majority opinion held that the state court did not have jurisdiction because it violated the Constitution's Commerce Clause by discriminating against out-of-state companies. Justice Field dissented from this decision, arguing that there was no discrimination and that states should be allowed to regulate their own businesses as they see fit. He argued that Congress has never given any indication of wanting to limit a State’s power over its own corporations and thus allowing such regulation would not violate the Commerce Clause. Furthermore, he noted how other States had similar laws regulating foreign corporations without being challenged on constitutional grounds before now. In conclusion, Justice Field believed that since Congress had not acted on this issue yet then it should be left up to each individual State’s discretion as long as they are treating all parties fairly under their regulations regardless of where those parties are located or incorporated.