Alexander Spengler (20 March 1827 – 11 January 1901) was a Swiss physician of German origin and the first physician specializing in tuberculosis in Davos.
Spengler was born as the eldest son of Johann Philipp Spengler, a teacher at a school in Mannheim. Starting in the autumn of 1846, he studied five terms at the University of Heidelberg.
Spengler had taken part in the Baden Revolution of 1848/1849 as a law student. After the defeat of the revolution, he was expatriated for desertion from the Grand Duchy of Baden in 1850. He fled to Zurich, where he studied medicine. In 1853, the stateless refugee got a job in Davos, which was remote at the time. His observation that pulmonary tuberculosis did not occur in Davos and that sick people returning home improved, marked the beginning of the development of the modern high-altitude health resort of Davos. Spengler was able to acquire Swiss citizenship in 1855.
Spengler was the father of Carl Spengler and Lucius Spengler, both pulmonologists in Davos.