Izidor Gross (25 July 1866 – 1942) was a Croatian chess master and hazzan.

Gross was born into a Jewish family in Kislőd, Hungary on 25 July 1866.

Gross published articles about chess problems in various domestic - foreign magazines and newspapers.

Gross organized in Karlovac, in 1912, first international chess tournament in the Balkans.

[1][2] As a Jew Gross was arrested and deported to Jasenovac concentration camp where he was killed in 1942 during the Holocaust,[3][4] together with his son Herman and daughter in law Julia.