Wilhelm Johann Eugen Blaschke (13 September 1885 – 17 March 1962) was an Austro-Hungarian differential and integral geometer.

His students included Shiing-Shen Chern, Luis Santaló, and Emanuel Sperner.

In 1916 Blaschke published one of the first books devoted to convex sets: Circle and Sphere (Kreis und Kugel). Drawing on dozens of sources, Blaschke made a thorough review of the subject with citations within the text to attribute credit in a classical area of mathematics.