Stelmaszyk, or Stelmaszek, is a Polish surname.
People Stelmaszek Rick Stelmaszek (1948–2017), an American baseball player
Stelmaszyk Agnieszka Stelmaszyk (born 1976), a Polish writer Jaclyn Stelmaszyk (born 1986), a Polish-Canadian rower Krzysztof Stelmaszyk (born 1959), a Polish actor
See also Stelmaszyk S.1 Bożena, a sport aircraft manufactured in 1928