Siegfried Kalischer (May 7, 1862 in Thorn – March 31, 1954 in Copenhagen) was a German neurologist and researcher.
Kalischer studied medicine at the Universities in Berlin and Würzburg, and graduated in 1885 with the dissertation "Zur Frage über den Einfluss der erblichen Belastung auf Entwicklung, Verlauf und Prognose der Geistesstörungen".
In 1891, he became the head of the clinic for nervous diseases in Berlin-Schlachtensee.