This study theorizes social innovation-based transitions to sustainable urban development from the perspective of the African urban condition, highlighting that large infrastructure and service provision deficits, poverty, inequality, heavy import dependence and the prevalence of dual formal–informal sector systems are key factors to account for in a just, sustainable urban African developmental transition. It identifies an opportunity space that can be leveraged for urban and broader transitions to sustainability on the continent by leveraging “economic ecosystems” for local scale social innovation-based development interventions. It theorizes that multi-level transitions to sustainability can be engendered by adopting an entrepreneurial state led approach at local scales by using economic ecosystems as the framework to (1) stimulate social innovation-based entrepreneurship that meets local and local–regional demands through decentralized, low cost, small-scale infrastructures, technologies and services, (2) leverage social innovation-based economic ecosystems for catalyzing multi-scalar transitions to sustainability, (3) recast the role of the entrepreneurial state, specifically in relation to social innovation and sustainable urban development (SUD) in Africa and (4) bridge formal–informal sector dualism. This framing prioritizes local economic development over centralized, state-led interventions that involve grand-scale masterplans, wholly new satellite cities and bulk infrastructure deployments in conceptualizing sustainable urban development transitions in Africa.