Sri Lanka is a country with several pressing nutritional issues, such as high wasting rates, micronutrient deficiencies, and non-communicable diseases. Fish is an important part of the Sri Lankan diet, and represent a rich source of protein, essential fatty acids, and several micronutrients important for food and nutrition security. However, existing data on the nutrient composition of fish in Sri Lanka is highly outdated and very limited. The aim of this study was to describe the nutrient composition of commonly consumed marine fish species from Sri Lanka and to assess the potential contribution of selected key nutrients to recommended nutrient intakes (RNI). A total of nineteen marine fish species were sampled during a survey with R/V Dr. Fridtjof Nansen around Sri Lanka from June to July, 2018. Species were categorized as either small (<25cm, n=12) or large (>25cm, n=7), and three composite samples from each species were analyzed using accredited methods at the Institute of Marine Research in Norway. Small species commonly consumed whole contained substantially higher concentrations of micronutrients such as calcium, iron, zinc, vitamin A, and EPA and DHA than larger species where only the fillet is consumed. Several species were identified to contribute ≥25% of the RNI of women of reproductive age for multiple nutrients essential for food and nutrition security in Sri Lanka. These data may represent an important contribution to the future development of the Sri Lankan food composition database.