Karen Armstrong (born 14 November 1944) is a British author and commentator of Irish Catholic descent known for her books on comparative religion. A former Roman Catholic religious sister, she went from a conservative to a more liberal and mystical Christian faith. She attended St Anne's College, Oxford, while in the convent and majored in English. She left the convent in 1969. Her work focuses on commonalities of the major religions, such as the importance of compassion and the Golden Rule.
Armstrong received the US$100,000 TED Prize in February 2008. She used that occasion to call for the creation of a Charter for Compassion, which was unveiled the following year.