The Greenland Ice Sheet is melting rapidly, increasing freshwater runoff to the coastal ocean around Greenland. Through this pathway, allochthonous material, including nutrients, sediments, and organic carbon, is transported to coastal waters. The impacts of these inputs on coastal carbon cycling are poorly resolved, and accelerating climate change prompts closer examination of the character and fate of allochthonous material reaching Arctic coasts. In this study, we have taken a closer look at quantity, quality, and transformation of organic matter (OM) in surface waters of an oligotrophic high Arctic fjord influenced by glacial and proglacial runoff. We examined dissolved, suspended, and sinking OM by combining in situ observations along a river-to-sea gradient with experiments quantifying bioavailable carbon fractions, production of transparent exopolymer particles (TEPs), and OM flocculation. We found that dissolved organic carbon (DOC) concentrations in glacial and proglacial river waters were comparatively low (