Starch analysis has increasingly been used to study ancient plant cultivation and consumption in many parts of the world, especially in America, Asia and the Near East. In this article we present the first evidence of fossil starch granules found on Finnish archaeological artefacts. Samples taken from three artefacts, a Late Stone Age pottery sherd from the Kiukainen culture, an Iron Age grinding stone from the 7th century AD and an 18th century AD tooth, yielded an abundance of plant starch granules and also possible evidence of food processing. The granules were studied using the latest microscopy techniques and compared against a database constructed of modern starch counterparts in order to identify the origins of the granules. The results indicate that a variety of starchy grain foods were already available by the Late Stone Age. They also suggest that cereal grains and other plant foods had been processed with the Iron Age grinding stone. Starch analysis of the 18th century tooth reveals traces of early potato consumption.