Doctor Jaroslav Kacmarcyk or Jaroslaw Kaczmarczyk, also spelled Iaroslav Karchmarchyk (1885–1944) was the head of the Lemko-Rusyn Republic from 1918 to 1920.
He was tried by the Polish government for anti-Polish agitation on June 6, 1921, and was acquitted.He was born in Binczarowa, in the Kingdom of Galicia and Lodomeria (present-day Poland).