Karlo Weissmann (14 February 1890 – 1953) was Croatian physician and founder of the first sanatorium in Osijek.
Weissmann was born in Virovitica to a Jewish family on 14 February 1890.
He completed elementary school in Osijek and Gymnasium education in Zagreb.
Weissmann graduated from the Medical University of Vienna.
During World War I he was recruited in the Austro-Hungarian Army and was stationed in Albania.