Ševko ef. Omerbašić was born in Ustikolina on 9th June 1945, BiH. After he finished his high school studies from Gazi Husref-bey's madrassa in Sarajevo, he graduated from the Faculty for Arabic language and Islamic studies, department for theology, program for missionary work and advertising at the Benghazi University in Beyda, in Libya.
He worked as imam in Rudo, the head imam in Ustikolina, BiH, and since 1975 as the head imam in Zagreb as well. Since 1988 he worked as the head imam for the Islamic Community in Croatia and Slovenia. He was also the first chairman of the Meshihat of the Islamic Community for Croatia and Slovenia and after the Islamic Community of Slovenia became independent at the end of 1994, he was elected the chairman of the Meshihat of the Islamic Community in Croatia. In 1999 he was appointed the mufti of Zagreb, and the mufti of the Islamic Community in Croatia.
He is the incumbent in several projects of the Islamic Community. Moreover, he played a very important role in having the Zagreb Mosque constructed, where he organized and established various activities. He is the author of several books, and, in the last few decades, he has dedicated himself to the research, study and writing about the Islam and Muslims in Croatia and the region. On this topic he wrote much appreciated work „Islam and Muslims in Croatia".