The study identified and assessed flood-prone communities in the core Niger Delta region of Nigeria using GIS (Geographic Information Science). Data for the study was obtained from both primary and secondary sources. The primary data was generated from the information obtained from the respondents through the administration of the questionnaire and the use of GPS to generate coordinates for the flood-prone communities in the core Niger Delta. The population of the study comprised of people in both rural and urban communities prone or ravaged by flood in the core Niger Delta states of Bayelsa, Delta, and Rivers. Random sampling technique (using blindfold) was used in the selection of 5 flood-prone communities from each of the 3 states. Random sampling technique was also used in the selection of 50 respondents from each of the 5 selected communities spread across each of the 3 selected states. This gave a sample of 250 per state totalling 750 in the 3 selected states. Furthermore, the geographic coordinates (i.e. Northings, Eastings, and Elevation) of the identified fifteen (15) flood-prone communities were taken at specific locations across the core Niger Delta. The result shows three (3) geo-referenced maps of flood-prone communities in the core Niger Delta. Further evidence from the study revealed that the respondents’ major source of livelihood was farming occupation (34.7%) and fishing occupation (21.0%), while respondents with low socioeconomic status dominated (53.0%) in the study area which implies that in the event of a flood disaster, coping with the flood disaster becomes a challenge due to the low socioeconomic status of the residents. Finally, the findings of the study reveal that the yearly occurrence of flood in the core Niger Delta region has led to the devastation or destruction of a large expanse of land including cultivated farmlands, crop yield before the flood occurrence was average (48.2%) and high (35.1%) while crop yield after the flood was very low (50.8%) and low (33.2%). The study, therefore, recommended the development or building of resilience to reduce the devastation of flood menace across communities in the core Niger Delta area and construction of structural measures like dams, culverts, drainages, and ditches to accommodate and reduce the runoff or overflow of floodwaters which causes severe social, economic and infrastructural damages or impacts in the flood-prone communities.