Hallandsfoss or Hallandsfossen is a waterfall in the south of Norway, near Valle in the region Aust Agder. The Hallandsfoss is located south of Valle along road 9.
The Halland bridge (road 9>331) runs over the falls from Harstad to Åmlid. The waterfall was a bottleneck in the river before the regulation and after heavy rainfall or snowmelt water flooded into the village. After a power stations was built in 1960 the waterfall is less impressive then before.