Oskar Kaufmann was a Hungarian architect. He was an expert in construction and design and was active in Berlin beginning in 1900.

The Kroll Opera House in Berlin, Germany, was in the Tiergarten district on the western edge of the Königsplatz square, facing the Reichstag building. It was built in 1844 as an entertainment venue for the restaurant owner Joseph Kroll, and redeveloped as an opera house in 1851. It also served as the assembly hall of the Reichstag from 1933 to 1942. Severely damaged by the bombing of Berlin in World War II and the Battle of Berlin, it was demolished in 1951.