Leopold Löwenheim [ˈle:o:pɔl̩d ˈlø:vɛnhaɪm] (26 June 1878 in Krefeld – 5 May 1957 in Berlin) was a German mathematician doing work in mathematical logic.

The Nazi regime forced him to retire because under the Nuremberg Laws he was considered only three quarters Aryan.

[1] Löwenheim (1915) gave the first proof of what is now known as the Löwenheim–Skolem theorem, often considered the starting point for model theory.

Leopold was the son of Ludwig Löwenheim, a mathematics teacher at the polytechnic in Krefeld and Elizabeth Röhn, a writer.

In 1881 the three of them left Krefeld first for Naples and then Berlin where Ludwig was a private scholar working on a comprehensive account of the influence of Democritus on modern science.