Carl Friedrich Theodor Strehlow (23 December 1871 – 20 October 1922) was a German Lutheran missionary and ethnologist in outback Australia who headed the Finke River Mission in Hermannsburg, Northern Territory from 1894.
Strehlow was born in Fredersdorf (today part of Zichow), Uckermark in the Prussian province of Brandenburg. From 1888 he was educated at the seminary of the Bavarian Lutheran Church in Neuendettelsau, Ansbach, graduating in 1891. He was preparing to migrate to the United States of America when he received a call from the Immanuel Synod in South Australia. He was ordained in July 1892 at Light Pass, South Australia.
Strehlow began his missionary work among the Dieri Aborigines in the Killalpaninna (Bethesda) Mission on the Cooper Creek in South Australia working for J. G. Reuther. He learned the Dieri language sufficiently that he was able to assist in finishing the translation of the New Testament in his two years there. In 1894 the Immanuel Synod bought the abandoned Finke River Mission at Hermannsburg and appointed Strehlow to head the mission there.  He immediately established order and daily discipline amongst the Christians in the community. He led it for 28 years until his death, and is recorded to have only ventured away further than Alice Springs four times. The first of these was in 1895 to marry his German fiance, Frieda Johanna Henrietta Keysser who had travelled separately to South Australia at Point Pass. They eventually had six children.
Strehlow learnt and documented the languages of the Arrernte and Luritja people, and published together with Moritz von Leonhardi a seven-volume work on their culture. He also worked to develop a dictionary and to translate Christian hymns and parts of the Bible into the Aranda language.
Sickened Strehlow died on his way to the Oodnadatta railway station at Horseshoe Bend near Titjikala. He is commemorated by the Carl Strehlow Memorial Hospital at Hermannsburg and the Strehlow Research Centre in Alice Springs.
- Strehlow: Die Grammatik der Aranda-Sprache, comparison of Aranda language with Dieri and Encounter Bay
- Strehlow: Woerterbuch der Aranda und Loritja Sprachen
- Strehlow, Kempe: Galtjindintjamea-Pepa Aranda Wolambarinjaka (book of worship)
- Strehlow: Pepa Aragulinja Aranda Katjirberaka (School primer, published 1928)
- Carl Strehlow: Die Aranda- und Loritja-Stämme in Zentral-Australien, Ed. Städtisches Völkerkunde-Museum Frankfurt am Main and Moritz Freiherr v. Leonhardi, Vol. 1-5, Frankfurt 1907-1920
- Ewangelia Lukaka. (Gospel of St. Luke in the Aranda or Arunta language.), 1925. London: B. & F.B.S.
- Ewangelia Taramatara(four gospels in Aranda), 1928 London: B. & F.B.S.
- Paul E. Scherer (2004). "STREHLOW, Carl Friedrich Theodor (1871-1922)". Webjournals. Evangelical History Association of Australia. Retrieved 5 April 2015.
- Veit, Walter F. (1990). "Strehlow, Carl Friedrich Theodor (1871–1922)". Australian Dictionary of Biography. volume (12 ed.). Canberra: Australian National University. Retrieved 5 April 2015.
- John Strehlow (2009). "Carl Strehlow". THE TALE OF FRIEDA KEYSSER. Retrieved 5 April 2015.
- "Carl Strehlow". Monument Australia. Retrieved 5 April 2015.
- Ted Strehlow: Journey to Horseshoe Bend