One of the key factors hindering the pace of electrification in Nigeria is the inadequacy of geospatial data and the limited application of geospatial-based electrification tools, such as the Open-Source Spatial Electrification Tool (OnSSET). This presentation focuses on Bauchi State, located in northeastern Nigeria, and Plateau State, in the north-central region, as case studies to illustrate the flexibility and analytical capability of OnSSET. The primary objective is to demonstrate the critical role of geospatial data and electrification modeling tools in supporting evidence-based electrification planning, particularly in identifying least-cost electrification pathways through the assessment of multiple electrification scenarios. A secondary objective is to underscore the relevance of geospatial data in informing electrification policy formulation and strategic energy planning.