Václav Treitz (also Wenzel Treitz) (9 April 1819 – 27 August 1872) was a Czech pathologist who was a native of Hostomice, Bohemia.
He studied medicine in Prague, and performed post-graduate studies in Vienna with Joseph Hyrtl (1810–1894). Subsequently, he practiced medicine at the Jagellonian University in Krakow, returning to Prague in 1855, where he became a professor and director of the institute of pathological anatomy.
Throughout his career, Treitz was a figure in the struggle for Czech nationalism. In 1872, at the age of 52, he committed suicide by ingesting potassium cyanide.
Treitz is remembered for his 1853 description of the suspensory muscle of the duodenum (musculus suspensorius duodeni), later being named the "ligament of Treitz" (also known as Treitz muscle). This ligament is a fibrous structure by which the duodenojejunal junction is fixed to the right crus of the diaphragm. His name is attached to several other anatomical terms: