Flooding is one of the most destructive natural hazards globally, with its frequency and severity amplified by climate change, land use alterations, and geomorphic characteristics of watersheds. This study assessed flood vulnerability in Hong Local Government Area (LGA), Adamawa State, Nigeria, through morphometric and relief analysis supported by Geographic Information System (GIS) techniques. The objectives were to delineate major basins in the study area, compute morphometric parameters, and prioritize them based on susceptibility to flooding. Six watersheds—Kwaleta, Kilange, Dugwaba, Diltil, Gashala, and Dzakwa—were delineated from Shuttle Radar Topography Mission (SRTM) Digital Elevation Model. Linear, areal, and relief parameters were calculated using standard morphometric formulae, and prioritization was conducted through composite rating (CR) values. Findings reveal significant variation across basins. Drainage density, stream frequency, infiltration number, and ruggedness number showed higher flood susceptibility in Kilange, Gashala and Dugwaba, while Kwaleta, Diltil and Dzakwa exhibited moderate to low vulnerability. These results are significant because the study area is ungauged, and morphometric analysis provides critical baseline data for flood management, land use planning, and runoff harvesting. It is recommended that local authorities integrate these findings into watershed management strategies, strengthen flood early-warning systems, and promote afforestation and soil conservation measures to reduce runoff and enhance resilience.