Janney v. The Columbian Insurance Company was a case heard by the United States Supreme Court in 1825. It involved an insurance policy issued to John Janney, who had purchased it from The Columbian Insurance Company of Philadelphia. After his death, Janney's executors sought to collect on the policy but were denied payment due to language in the contract that excluded coverage for losses caused by "the act of God." In its decision, the court held that this exclusionary clause did not apply because there was no evidence that any such act had occurred and thus could not be used as a defense against paying out on the claim. Furthermore, they ruled that if an insurer wishes to exclude certain risks from their policies then they must make those exclusions clear and unambiguous so as not to mislead customers into believing they are covered when they are actually not. This ruling established important legal precedent regarding how insurers should communicate with their customers about what is or isn't covered under their policies.

In Janney v. The Columbian Insurance Company, the Supreme Court was asked to decide whether a policy of insurance issued by the defendant company covered losses incurred when goods were stolen from an insured vessel while it was in port. Justice Story delivered a dissenting opinion arguing that the language of the policy should be interpreted broadly and not limited to only those losses caused by perils at sea. He argued that if this interpretation were adopted, then all other policies would have similar broad coverage as well, which he believed would benefit both insurers and insureds alike. Furthermore, he noted that such an interpretation is consistent with prior case law on maritime insurance contracts and thus should be applied here as well.