Barnhusviken (Swedish for "the Orphanage Bay") is a body of water in central , Sweden. Separating the island Kungsholmen from the mainland district Norrmalm north of it, it connects Karlbergssjön to Klara Sjö.
Together with Karlbergskanalen, Karlbergssjön, and Klara Sjö, Barnhusviken constitute the nameless body of water which separates Kungsholmen from the city districts Norrmalm and and the northern suburb Solna.
The northern shore, entirely occupied by the Klarastrandsleden motorway and eight rows of railway tracks, is not accessible to pedestrians, but, in contrast, the southern shore offers a section of the walk stretching some 2 km from the and all the way along the northern shore of Kungsholmen.
Just like the bridge Barnhusbron spanning across it and several other local structures, the former bay was named in the 1860s after an orphanage (barnhus, literally "children-house") relocated from Riddarholmen to the neighbourhood on its northern shore in the 1630s.
It is called a bay simply because it used to be a bay before continuous land filling transformed it into the narrow canal it is today. On maps from the early 19th century it is labelled Rörstrandssjön ("Lake of Rörstrand") after the vicinity to the porcelain factory of Rörstrand.
Several prominent buildings line-up along the shores of Barnhusviken:
Coordinates: 59°20′05″N 18°02′53″E / 59.33472°N 18.04806°E