Bavariahaus, Heritage monument in Wilhelmshaven, Germany.

Bavariahaus is a five-storey corner building at Roonstraße and Oldenburger Straße in Wilhelmshaven, built 1911–1913 for the Altonaer Bavaria Brewery. Architects Heinrich Wilhelm Behrens and Friedrich Neumark designed it in Art Nouveau style as a reinforced concrete skeleton structure by Paul Kossel & Cie. Its facade alternates plaster and brickwork, with projecting and recessed elements breaking symmetry.

The Altonaer Bavaria Brewery bought the plot from the painter Takenberg and had the building erected between 1911 and 1913; the Heimatlexikon Wilhelmshaven gives these years, while the monument directory dates the five-storey corner building to around 1905. It stands at the corner of Roonstraße and Oldenburger Straße, and Roonstraße, named after Field Marshal Graf Albrecht von Roon, was once Wilhelmshaven's main shopping street.

The name comes from the Altonaer Bavaria Brewery, which bought the land from the painter Takenberg and had the building erected as a residential and commercial house. Today the ground floor holds restaurants and shops, and the corner building with entrances on Roonstraße and Oldenburger Straße is seen as the centre of Wilhelmshaven's emerging South Quarter.

The building is located in Wilhelmshaven's central area and is easily reached on foot when exploring the city. Since it is a protected heritage site, visitors should enjoy the exterior view and respect any publicly accessible areas nearby.

The Bavariahaus was commissioned by the Altonaer Bavaria Brewery, which bought the plot from the painter Takenberg. The Bremen architects Heinrich Wilhelm Behrens and Friedrich Neumark designed it, and the firm Paul Kossel & Cie built it as a reinforced concrete skeleton structure.