Siniša Krajač was born on 13 August 1968 in Zagreb. He holds a master’s degree in kinesiology with the title of professor of physical and health culture, and he earned his academic status at the Faculty of Kinesiology, University of Zagreb. He speaks English.

As a student, he worked at the football school of NK Lokomotiva, where he himself grew up in sport spirit under the guidance of the legendary coach Ilija Lončarević.
He came to the Croatian Olympic Committee in 2001 from the Ministry of Defense of the Republic of Croatia, namely from the Sports Department of the General Staff of the Armed Forces of the Republic of Croatia. Prior to that, he was employed by the Ministry of Defense as Head of the Verification Department and Head of analytics at the Security and Information Service. During the 2nd Military World Games (CISM) in Zagreb, he worked as Head of the Water Sports Group in Zagreb.

Through two decades of work at the Croatian Olympic Committee, he held several important positions: Acting Director of the National Sports Federations Program Office (2004-2007), Head of the Research and Development Program Enhancement Department in two terms (2001-2004 and 2007-2010) and came to his current position as Assistant Secretary General for Local Sports Programs Office.
He is a participant of the Homeland War and one of the founders of the MIG volunteer student unit (“volunteer unit for special assignments of the Ministry of the Interior of the Republic of Croatia”) which was later attached to the composition of the ALFA Special Police Unit. As a reserve and active special forces officer, a member of ALFA’s from 1991 to 1993, he passed numerous Croatian battlefields.
After the earthquake in Banovina in late 2020, together with representatives of the local community, he organized a fundraising for athletes, their families and sports associations from the area and, after involvement of IOC and EOCs in the action, he was extremely responsible for opening of the first prefabricated multi-sports hall in Petrinja.
Siniša Krajač is the sixth Secretary General in the almost 30-year history of the Croatian Olympic Committee, and he took office on 10 May 2021.