He was the eldest son of Christian Axel Dahl (1878-1918), a naval officer, and Elise Augusta Steen (1879-1952).

He studied at the Norwegian National Academy of Craft and Art Industry (1924–25) under Eivind Nielsen, at the Norwegian National Academy of Fine Arts under Axel Revold and Halfdan Strøm (1925–27) and under Olaf Willums (1929–32).

Dahl was a teacher at the Norwegian National Academy of Craft and Art Industry from 1945 to 1974.

His illustrations include books by Bjørnstjerne Bjørnson, Henrik Wergeland, Mark Twain, Jules Verne and Stefan Zweig.

He is represented with several works at the National Gallery of Norway including Napolitansk gårdsrom, Piazzale Mercato (1932), På broen (1932), Gjøglerfamilie (1933) and Selvportrett (1933).