Stjepan Razum, a priest, Catholic theologian and Church historian, was born on 16 December, 1960 in Konšćica, Samobor Municipality, Croatia. He attended primary school in Sveti Martin pod Okićem, while he attended the archdiocesan classical gymnasium attended in Zagreb from 1975 to 1979. He graduated from the Catholic Theological Faculty of the University of Zagreb in 1986. He also earned a degree in diplomatics and palaeography at the Vatican Archives in 1994, and he earned a doctorate in Church history at the Pontifical Gregorian University in Rome in 1995. Since 1995, he has been employed in the Croatian State Archives, with an office at the Archdiocesan Archives of Zagreb, which is a department of the former.

He has been the head of the Archdiocesan Archives of Zagreb since 1996. In 2008 he gained the title of a senior archivist, and later he was appointed archival consultant in 2010. He is a member of the editorial office of several scholarly and cultural journals, and a number of initiatives involved in the promotion of historical and cultural research. He did not engage in politics in life, but on a personal level he opposed to the then communist regime as a divinity student and then young priest.