Fish, in Bangladesh where malnutrition remains a significant development challenge, is an irreplaceable animal-source food in the diet of millions. However, existing data on the nutrient composition of fish do not reflect the large diversity available and have focused on only a few select nutrients. The purpose of this study was to fill the gaps in existing data on the nutrient profiles of common fish in Bangladesh by analysing the proximate, vitamin, mineral and fatty acid composition of 55 fish, shrimp and prawn species from inland capture, aquaculture and marine capture fisheries. When comparing species, the composition of nutrients of public health significance was diverse. Iron ranged from 0.34 to 19. mg/100. g, zinc from 0.6 to 4.7. mg/100. g, calcium from 8.6 to 1900. mg/100. g, vitamin A from 0 to 2503. μg/100. g and vitamin B12 from 0.50 to 14. μg/100. g. Several species were rich in essential fatty acids, particularly docosohexaenoic acid in capture fisheries species (86-310. mg/100. g). The potential contribution of each species to recommended nutrient intakes (RNIs) for pregnant and lactating women (PLW) and infants was calculated. Seven species for PLW and six species for infants, all from inland capture, and all typically consumed whole with head and bones, could potentially contribute ≥25% of RNIs for three or more of these nutrients, simultaneously, from a standard portion. This illustrates the diversity in nutrient content of fish species and in particular the rich nutrient composition of small indigenous species, which should guide policy and programmes to improve food and nutrition security in Bangladesh.