The ruined building was made safe against the elements and partially refurbished in the 1960s, but no attempt at full restoration was made until after German reunification on 3 October 1990, when it underwent a reconstruction led by architect Norman Foster. After its completion in 1999, it once again became the meeting place of the German parliament: the contemporary Bundestag. Construction of the building began well after the unification of Germany in 1871. Starting in 1871, and for the next 23 years, the parliament met in the former property of the Königliche Porzellan-Manufaktur Berlin, at Leipziger Straße 4. In 1872 an architectural contest with 103 participating architects was carried out to erect a new building, a contest won by Ludwig Bohnstedt. The plan incorporated the Königsplatz (today's Platz der Republik), which was then occupied by the palace of a Polish-Prussian aristocrat, Athanasius Raczyński. Unfortunately, that property was unavailable at the time.

In 1882, another architectural contest was held, with 200 architects participating. This time, the winner—the Frankfurt architect Paul Wallot—would actually see his Neo-Baroque project executed. The direct model for Wallot's design was Philadelphia's Memorial Hall, the main building of the 1876 Centennial Exhibition. Wallot adorned the building's façade with crowns and eagles symbolising imperial strength.

On 29 June 1884, the foundation stone was finally laid by Wilhelm I, at the east side of the Königsplatz. Before construction was completed by Philipp Holzmann A.G. in 1894, Wilhelm I died (in 1888, the Year of Three Emperors). His eventual successor, Wilhelm II, took a more jaundiced view of parliamentary democracy than his grandfather. The original building was acclaimed for the construction of an original cupola of steel and glass, considered an engineering feat at the time. But its mixture of architectural styles drew widespread criticism.

In 1916 the iconic words Dem deutschen Volke ("To the German People") were placed above the main façade of the building, much to the displeasure of Wilhelm II, who had tried to block the adding of the inscription for its democratic significance. After World War I had ended and Wilhelm had abdicated, during the revolutionary days of 1918, Philipp Scheidemann proclaimed the institution of a republic from one of the balconies of the Reichstag building on 9 November. The building continued to be the seat of the parliament of the Weimar Republic (1919–1933), which was still called the Reichstag. Up to 42 protesters died during the Reichstag Bloodbath of 13 January 1920, when workers tried to protest against a law that would restrict their rights; it was the bloodiest demonstration in German history.