Willem Sonneveld was born in Utrecht, The Netherlands on 28 juni 1917. When he was nineteen he became secretary to the famous Dutch singer Louis Davids; it was the beginning of his career in cabaret. He was fired when Davids discovered that Sonneveld was doing the performances that Davids didn't want to do.

From 1943 he had for ten years his own cabaret company with people like Conny Stuart, Hettie Blok, Joop Doderer, Kees Brusse, Hans van Maanen, Hella Haasse and Albert Mol.