Slettmarkpiggen is a mountain on the border of Vang Municipality and Lom Municipality in Innlandet county, Norway. The 2163 m tall mountain is located in the Jotunheimen mountains within Jotunheimen National Park. The mountain sits about 37 km northeast of the village of Øvre Årdal and about 27 km northwest of the village of Beitostølen. The mountain is surrounded by several other notable mountains including Store Svartdalspiggen to the northeast; Mesmogtinden, Langedalstinden, Kvitskardtinden, and Torfinnstindene to the east; Galdeberget and Oksedalshøi to the southwest; Slettmarkkampen to the west; Snøholstinden and Store Rauddalseggi to the northwest; and Storådalshøi to the north.