Mary Howgill (1623-before 1681) was a prominent early member of the Religious Society of Friends (Quakers) in England. She is best known for her public defense of Quakers in a 1656 letter to Oliver Cromwell. She delivered the letter in person and subsequently had a long discourse with Cromwell. She began the letter: The letter was written during a time of religious persecution, and challenges political and religious authorities that punished statements of religious conscience with confiscation of property, physical violence, and imprisonment.