Murphy, Administratrix v. Victor Sewing Machine Company is a United States Supreme Court case that was decided in 1884. The case involved a dispute between the plaintiff, Mary Murphy, and the defendant, Victor Sewing Machine Company. Murphy was the administratrix of the estate of her late husband, who had purchased a sewing machine from the defendant. The machine was defective and caused her husband's death. Murphy sued the defendant for damages, claiming that the machine was defective and that the defendant had failed to warn her husband of the potential danger. The Supreme Court held that the defendant was liable for the damages, as it had failed to provide adequate warnings of the potential danger of the machine. The Court also held that the defendant was liable for the damages even though the machine had been sold to the plaintiff's husband without any express warranty. The Court's decision established that a manufacturer can be held liable for damages caused by a defective product, even if the product was sold without any express warranty. This case established the principle of strict liability, which holds that a manufacturer is liable for any damages caused by a defective product, regardless of whether the manufacturer was negligent or not. This case is still cited today as an important precedent in product liability law.

In Murphy v. Victor Sewing Machine Company, the Supreme Court was asked to decide whether a patentee who had assigned his rights in an invention could sue for infringement of that same invention. The majority opinion held that he could not, as it would be inequitable to allow him to benefit from both the assignment and a lawsuit based on the same subject matter. Justice Field dissented from this decision, arguing that there is nothing inherently unjust about allowing someone with an ownership interest in a patent to bring suit against another party for infringing upon their rights. He further argued that if Congress intended otherwise they would have explicitly stated so in the Patent Act itself; since they did not do so, it should be assumed that such suits are permissible under law.