Flakstadelva is a river in Innlandet, Norway. Its headwaters lie in the bog areas around Gråberget. From there it runs in a southerly direction and forms the Nybusjøen, which discharges into the Lundsbekken river. The river flows in a v-shaped valley which twists before its mouth on the Lundsbekken. The river's erosion has exposed the lower Cambrian and middle Cambrian rock formations in that region.