Information on the energy density of prey is critical for estimating food requirements and consumption by predators and modelling energy flux through food webs (Van de Putte et al., 2006). We compiled energy density values for 121 marine species or genera from 12 published sources. The dataset encompasses 71 benthic and pelagic fish, 29 crustaceans, 15 cephalopods, 2 elasmobranchs, 2 jelly fish and 1 salp, sampled in the central and Northeast Atlantic and in the Mediterranean Sea between 1992 and 2017. Data were collected from studies that measured energy density directly by bomb calorimetry, and those studies that measured the proximate composition (i.e. the percentage of proteins, lipids and carbohydrates) of sampled tissues and converted these percentages into energy using combustion equivalents reported in the literature. When available, we reported energy density (or mean density, for samples with more than one individual) as a function of dry and wet weight, and the moisture percentage of samples. For each data record, we also provided the sampling location, geographic coordinates, month and year of sample collection, method of sample collection, taxonomic ranks (phylum, class, order, family), number and size (or size range) of sampled organisms, as well as the reference and DOI of the original data source, for further details on the samples analysed and/or the analytical techniques used.