Theo Findahl (Theodor Leonard Findahl; 24 August 1891 – 19 May 1976) was a Norwegian teacher and journalist. He was born in Tvedestrand. He worked as teacher until 1939, and from then as a foreign correspondent for the newspaper Aftenposten. He is particularly remembered for his reports from Germany on 5 and 7 April 1940, when he was a news correspondent in Berlin. These reports warned about the German attack on Norway, but the message was not taken seriously by the Norwegian Commanding Admiral.
Among his books are Kloster og arena. Streiftog i Spanien from 1926, Den gule keiservei. Inntrykk fra Japan from 1933, Undergang. Berlin 1939–1945 from 1945, and Lange skygger. Dagbok fra krigens Berlin 1939–1945 from 1964.