**Hugo Dyonizy Steinhaus** (1887 - 1972) was a Polish mathematician.

Steinhaus was professor of Lwow (1920-1941) and Wroclaw (1945-1961) Universities and then University of Notre Dame (Indiana) (USA, 1961-1962), University of Sussex (1966), member of PAU (Polish Academy of Abilities) (since 1945) and PAN (Polish Academy of Science) (since 1952), and many international science societies and science academies.

He was cofounder of the so called Lvov school of mathematics and author of many works (over 170) in the fields of mathematical analysis, probability theory and statistics.

He also wrote some introductory texts on mathematics: *Czym jest, a czym nie jest matematyka* (*What is, and what is not mathematics*)(1923), *Kalejdoskop matematyczny* (*Mathematical Kaleidoscope*)(1938), *Sto zadan* (*One hundred questions*)(1958), *Orzel czy reszka* (*Heads or Tails*) (1961).

With Stefan Banach, he founded the magazines Studia Mathematica (1929) and by himself Zastosowania matematyki (The Application of Mathematics) (1953).

**See also:** Steinhaus polygon notation.