Semmeldalen is a valley in Nordenskiöld Land at Spitsbergen, Svalbard. It has a length of about 8 kilometers, and is a tributary valley to Reindalen.[1] The river Semmeldalselva flows through the valley.[2] At the eastern side of the valley is the slope Høgsnythallet and the mountain Høgsnyta.[3][4] The valley is partly included in the Nordenskiöld Land National Park.