Theodor August Christian Sørensen (25 May 1873 – 2 September 1959) was a Norwegian missionary known for his work in Tibet.

[1] He wanted to travel within Tibet, but as this was rejected by the British colonial power, he moved to Chengtu, Chinese Manchu Empire in 1896.

[3] From 1899 to 1923 he lived and worked for the China Inland Mission in Tatsienlu, Szechwan,[2] where he established the Tibetan Religious Tract Society in early 1918.

[4] He did not particularly succeed as a missionary, but conducted several longer travels in Eastern Tibet and became known for collecting Tibetan scripture.

Upon returning to Norway in 1923, he donated a 314-volume collection of Tibetan Buddhist canon to the University of Christiania.