Katherine Augusta Westcott Tingley (born July 6, 1847, Newbury, Massachusetts; died July 11, 1929, Visingsö, Sweden) was a social worker and prominent Theosophist. She was the leader, after W. Q. Judge, of the American Section of the Theosophical Society. She founded and led the Theosophical community Lomaland in Point Loma, California.
In 1895, disputes between Judge and Annie Besant led to a split, with Judge taking most of the American section with him, and leading it for one year until his death in 1896. At that point Tingley became the new head of the Universal Brotherhood and Theosophical Society, although her identity was concealed for one year. In 1898, a group of roughly 200 theosophists led by Ernest Temple Hargrove seceded from Tingley's organization, and formed a rival group based in New York City. 
She conducted two theosophical crusades around the world. She was the founder of the International Brotherhood League, and also of the Summer Home for Children, Spring Valley, New Jersey, of a home for orphan children in Point Loma, California, and of several academies for boys and girls in Cuba. She did considerable relief and emergency hospital work after the Spanish–American War and was instrumental in establishing hospitals in Manila and Cuba. 
On February 13, 1900, she transferred the Society's international headquarters from New York City to a new colony she called Lomaland, located in the Point Loma community near San Diego, California. Her settlement included Raja-Yoga School and College, Theosophical University, and the School for the Revival of the Lost Mysteries of Antiquity.
In 1913 she founded the Parliament of Peace and Universal Brotherhood and in 1919 the Theosophical University at Point Loma. She established several theosophical branch centers in America and in Europe, and also a summer school for children at Visingsoe, Sweden. She was the editor of the Theosophical Path. Many theosophical magazines were published under her direction in Germany, Holland and Sweden. She was the author of "Theosophy and Some of the Vital Problems of the Day," "Marriage and the Home," "Theosophy, the Path of the Mystic." 
In 1888 she married Philo B. Tingley, inventor, and lived at Point Loma, California. 
|Wikimedia Commons has media related to Katherine Tingley.|
- Binheim, Max; Elvin, Charles A (1928). Women of the West; a series of biographical sketches of living eminent women in the eleven western states of the United States of America. p. 88. Retrieved 8 August 2017. This article incorporates text from this source, which is in the public domain.
- San Diego Historical Society: Katherine Tingley biography