Uphagen House (Polish: Dom Uphagena) is an 18th century merchant house located in Gdansk, Poland. The house was originally owned by Johann Uphagen in 1775 before becoming a museum in 1911. Located at 12 Długa Street in Gdańsk, the house is one of only a few 18th century merchant town houses in Europe open to visitors.
The house was originally purchased in 1775 by the merchant Johann Uphagen. Following this purchase the town house underwent a number of changes which adapted it to the needs of a wealthy 18th century merchant in Gdansk. In 1802 Uphagen died and the house was passed down through a number of generations of the Uphagen family throughout the 19th century. In 1911 the house was converted into a museum which it remained until 1944, when a number of its furniture was removed by the German curators who were installed after the German invasion of Poland. As with much of the city of Gdansk, Uphagen House was destroyed during the Soviet advance and subsequent German retreat of 1945.
The modern day building at 12 Długa Street was rebuilt within after the second world war however it was not until 1998 that the house was opened to visitors.