This submission contains data on local ecological knowledge of marine fishes collected in Roviana Lagoon, Western Province, Solomon Islands, between 2014 and 2015. At four communities (from west to east: Ilangana, Nusa Roviana, Baraulu, and Nusa Hope)—those in the west being closer to the provincial town Munda—eight focus groups were held each, representing four age groups (13-19, 20-35, 36-55 and >55 years) divided by gender. Participants in each age group were selected by each village leadership to participate in the focus groups under the premise of being a "competent marine harvester" for their age group and gender. Participants were asked to free-list all local names of marine species (particularly fishes) known to them, thus allowing each respondent to list as many responses as they wanted. Then, they were instructed to assign the free-listed names into broader categories through pile sorting if possible, which represented local taxonomic groupings, and provide information on the characteristics underlying classification into each of the broader categories. To assess what kind of domains of knowledge respondents drew on in their classification, the descriptors used to characterize categories were assigned to one of five domains: taxonomic (e.g. if respondents used a generic term such as mara [carangids] to describe a group), appearance (i.e. for information on morphology, color or smell), behavior (e.g. schooling), habitat (e.g. deep water, seagrass), or utilitarian characteristics (e.g. bait, gear used to catch a species, or way of preparation). The data comprises two tables.