Borgarfjörður is a fjord in the west of Iceland near the town of Borgarnes. The waters of Borgarfjörður appear to be calm, however the fjord is on the contrary a rather dangerous part of the sea because of its undercurrents and shallows.
There are many flat islands lying in the fjord, but for the most part they are uninhabited.
The land around the fjord has been inhabited since the time of Icelandic settlement. Events in the Icelandic sagas such as that of Egill Skallagrímsson are situated here.
The name of the fjord seems to come from the farm of Borg, which according to the sagas was founded by Egill's father Skallagrímur, who took the land around the fjord and accordingly gave the fjord the name of Borgarfjörður.