Climate and land use/land cover (LULC) changes are reshaping water availability and quality across Sub-Saharan Africa (SSA), where data scarcity and limited technical capacity complicate sustainable water resources management. Hydrological models integrated with remote sensing (RS) and geographic information systems (GIS) provide essential tools to quantify and simulate these changes; however, no comprehensive synthesis has systematically assessed their application in SSA. This review investigates 165 peer-reviewed studies published between 2000 and 2025, following the PRISMA guidelines. The results show that the Soil and Water Assessment Tool (SWAT) dominate applications (75%), with WetSpass-M and HEC-HMS each accounting for approximately 17%. Research efforts are disproportionately concentrated in Ethiopia (49.7%), whereas West and Central Africa remain underrepresented. Key challenges, including sparse hydro-climatic data, weak calibration and validation, limited modelling expertise, and inconsistent methodological standards, continue to constrain progress. Simultaneously, promising innovations are emerging, including RS and Machine learning integration, ensemble climate modelling, and cloud-based platforms such as the Google Earth Engine. Strengthening automatic hydro-climatic observation networks, expanding regional calibration datasets, and promoting participatory and integrated modelling frameworks that bridge physical, socio-economic, and ecological dimensions will be critical for advancing evidence-based, climate-resilient water management in SSA's drylands.