The Snowy Owl (Bubo scandiacus) is a rare resident species in Iceland and nests have been found intermittently. Nests are unusual because lemmings (Dicrostonyx spp. and Lemmus spp.), the primary prey of the Snowy Owl across much of its distribution, do not occur in Iceland. We studied summer diets by analyzing pellets from three areas in Iceland where owls were detected; breeding was confirmed at two of these sites. We identified 257 prey items (total mass of 73.6 kg) of at least 13 species. Birds made up most of the diet (96.5% by number). The Rock Ptarmigan (Lagopus muta) was the primary prey species (30.4%). Shorebirds were important prey (46.2%), and passerines (5.1%), as well as waterfowl (6.3%), were also taken. Wood mice (Apodemus sylvaticus; 2.7%) and Arctic fox pups (Vulpes lagopus; 0.8%) were taken occasionally. Adult prey birds made up 60.3% and nestlings 36.3% of the diet by number.