Franjo Klein (1828–1889) was a prominent architect known for his significant contributions to early and mature historicism in Croatia, particularly in Zagreb during the 1860s and 1870s. Born in Vienna, Klein received training in building and stone carving trades before pursuing architecture studies at the Academy of Fine Arts. He relocated to Croatia in 1851 and worked for the Varaždin-Đurđevac Regiment in Bjelovar for eight years before transferring to Zagreb in 1859. During his time in Bjelovar, Klein designed and constructed several public buildings, although surviving records supporting his attribution are scarce. Notable among his early works is the Church of the Assumption of the Blessed Virgin Mary in Molve, built between 1855 and 1862, showcasing Rundbogenstil architecture. In Zagreb, Klein undertook the construction of significant landmarks, including the Zagreb Synagogue, commenced in 1866 and completed the following year, and the Zagreb Orthodox Cathedral on Petar Preradović Square. In collaboration with Janko Grahor, Klein founded the construction company Grahor and Klein in 1868, which later became Grahor and Sons after Klein's departure in 1886. Throughout his career, Klein left a lasting legacy in Croatian architecture, shaping the architectural landscape of Zagreb and beyond.

Franjo Klein - Wikipedia