Urddalsknuten or Urdalsknuten is a mountain that lies on the border of the municipalities of Sirdal in Vest-Agder county and Valle in Aust-Agder county, Norway. The mountain is located in the Setesdalsheiene mountain range, and at , it is the highest mountain in Vest-Agder county. The mountain lies about west of the village of Valle. The lakes Botnsvatnet, Kolsvatnet, and Rosskreppfjorden surround the mountain to the northeast and south and the mountain Bergeheii lies directly to the north.