Palmer v. Allen was a United States Supreme Court case that addressed the issue of whether an individual could be held liable for debt incurred by another person, even if they had not signed any documents or otherwise agreed to assume responsibility for such debt. The court ultimately ruled in favor of Palmer, finding that he was not responsible for the debts of his deceased brother-in-law and could not be held accountable as a third party guarantor. In its decision, the court noted that there must be clear evidence demonstrating an agreement between two parties before one can be found liable for another's obligations; mere familial relationships are insufficient grounds on which to base liability claims. This ruling established important precedent regarding personal financial responsibility and has been cited in numerous cases since then.

In Palmer v. Allen, the Supreme Court was asked to decide whether a deed of trust that had been executed in 1797 by an individual named John Palmer could be enforced against his son, William Palmer. The majority opinion held that it could not because the deed did not contain language indicating that it was intended to bind future generations and thus should only apply to John's lifetime. Justice Johnson dissented from this decision on the grounds that there is no requirement for such language in deeds of trust and therefore they should be binding upon successors unless otherwise specified in the document itself or prohibited by law. He argued further that if such a restriction were imposed then many trusts would become unenforceable due to their age and lack of explicit wording regarding succession rights; this would lead to injustice as those who are entitled under these instruments may never receive what is rightfully theirs.