Dynjandi (, also known as Fjallfoss ) is a waterfall located in Arnarfjörður in the Westfjords region of Iceland. It is the largest waterfall in the Westfjords and has a total height of . Below it are five other waterfalls: Háifoss, ÃÂðafoss, Göngufoss, Hundafoss and Bæjarfoss.
Dynjandi and other waterfalls in Dynjandisá and their surroundings were protected as natural monuments in 1981.
Dynjandisheiði is a mountain pass over the falls that contains the first-built car-accessible road to ÃÂsafjörður.