Rock art research in Northern Europe has found few opportunities to highlight the creation and use of rock art through informed methods. Most rock art traditions seem to have ended thousands of years before any historical sources inform us about people’s life-worlds. The exception to this is ample post-Reformation sources that connect cup marks with elves: light fairy creatures who were easily disturbed and could cause sickness and ill fortune if they became annoyed. This paper highlights this body of belief through historical and oral sources and through archaeological evidence. I argue that Early Modern elf folklore may very well be based in older traditions which found new expressions through the Reformation and the Danish and Swedish state religion – Protestantism.