Waldemar Lorentzon was a Swedish artist born in Halmstad in 1899.

Lorentzon was discovered at an amateur exhibition by Egon Östlund, who introduced him to the artist Gösta Adrian-Nilsson. After a few years of studying at the Althin School of Painting, Lorentzon moved to Paris in 1924 to study at Fernand Léger's Académie Moderne, where he was taught Cubism. In 1925, he participated in the major international exhibition L'Art d'Aujourd'hui with abstract art by painters such as Picasso, Severini and Léger himself. In 1929 Lorentzon formed Halmstad gruppen with the brothers Axel and Erik Olson, Sven Jonson, Esaias Thorén and Stellan Mörner. The group began as cubists, but during the 1930s moved more towards surrealism, which they were the first to introduce in Sweden.

Lorentzon's work was characterised by a modified cubism and later a classicism where he often depicted athletes and sailors. His surrealism moves between marine symbols and cosmic visions, expressing a swarming religiosity rather than speaking the language of the subconscious soul.