Dr. Ruth Katherina Martha Pfau, FCM was a German–Pakistani Catholic religious sister and physician who was a member of the Society of the Daughters of the Heart of Mary. She emigrated from Germany in 1961 and devoted more than 55 years of her life to fighting leprosy in Pakistan. Dr. Ruth Pfau contributed to the establishment of 157 leprosy clinics across Pakistan that treated over 56,780 people. Fazaia Ruth Pfau Medical College and Dr. Ruth Pfau Hospital are named after her in Karachi.