Zsombor Kálnoki-Kis was born on 23rd September 2001 in Budapest. His father, Attila Kálnoki-Kis, is a multiple pentathlon world champion and sports journalist, and his brother, Dávid Kálnoki-Kis, is an experienced NB I footballer who has played for MTK, Újpest, Kispest and Zalaegerszeg, and last season he played for NB II team Budafoki MTE.

Zsombor began his career at Vasas, more precisely at the Kubala football academy, before moving to Újpest, where he scored 21 goals in 59 matches for the NB III reserve team. He then went to study in the United States, where he was a scholarship student in Birmingham, Alabama, spending two years in America playing in the NCAA, the Division I university league.

After returning from the United States, he signed with Nafta Lendava, the affiliate team of ZTE FC in Slovenia, where he scored two goals in 33 league games last season - his extraordinary goal against Celje went viral on the internet.