Rapid urbanisation in secondary cities across sub-Saharan Africa increasingly challenges the effectiveness of urban land governance systems and sustainable spatial planning. This study assessed the interactions between urban expansion dynamics and land governance performance in Mzuzu City using an integrated geospatial and institutional analytical framework. Multi-temporal Landsat imagery from 1990, 2000, 2010, 2020 and 2025 was classified to quantify land use and land cover (LULC) changes, while alluvial transition analysis examined land conversion pathways. Spatial determinants of urban growth were investigated using road proximity buffers, directional expansion analysis, slope suitability assessment and zoning overlay analysis. Institutional performance was evaluated through policy review, stakeholder assessments, governance network analysis and the development of an Urban Land Governance Index (ULGI). The results revealed substantial environmental transformation, with forest and vegetation declining by 47.9% and 45.5%, respectively, while built-up land and bareland increased by 384.6% and 239.4%. Urban expansion exhibited a strong accessibility bias, with 34.2% of new developments occurring within 200 m of major roads and growth concentrated towards the northern (31.4%), north-western (24.7%) and eastern (21.3%) urban fringes. Approximately 18.6% of residential developments encroached upon commercial, industrial and forest-designated land, while 23.6% expanded onto slopes exceeding 7°, increasing environmental vulnerability. Governance assessment produced a moderate ULGI score of 55.73, characterised by high tenure security (74) but weak enforcement effectiveness (43). The findings demonstrate that urban governance challenges in Mzuzu are fundamentally institutional rather than legislative and highlight the need for integrated land information systems, stronger development control and improved coordination between statutory and customary institutions.