Otto Jírovec (January 31, 1907 – March 7, 1972[1]) was a Czechoslovak professor of parasitology and protozoology.
During the war he worked as head of the Parasitology Laboratory at the State Health Institute.
In his professional work he focused in particular on the study of parasitic protozoa, both in temperate and in tropical regions.
One of his most important discoveries was the pathogen causing Pneumocystis pneumonia, which he made with the pathologist Dr. M. Vaňek in 1953.
He was a member of the Royal Czech Society of Sciences, Masaryk Academy of Labor and the Czechoslovak National Council research.