Krishnammal Jagannathan (born 16 June 1926) is an Indian social activist from the state of Tamil Nadu. She and her husband, Sankaralingam Jagannathan (1912 – 12 February 2013), protested against social injustice and they are Gandhian activists. Her work includes upliftment of the landless, and the poor; she has sometimes fought against governments as well as big industries. She was earlier involved in the Indian independence movement, along with her husband, and was also a close associate of Vinoba Bhave. In 2008 she received the Right Livelihood Award, which she shared with her husband. She was given the Padma Bhushan; India's third highest civilian award; in 2020.