This study examines (i) how top‐level managerial institutional ties drive corporate sustainability strategies of emerging market firms operating under conditions of institutional adversity; (ii) the impact of corporate sustainability strategies on market performance; and (iii) the moderating role of financial resource slack on the relationships between corporate sustainability strategies and market performance. The study builds from institutional development logic and the structure–conduct–performance paradigm. Primary data are collected from 300 firms operating in a major sub‐Saharan African market. Findings show that top‐level managerial institutional linkages with regulatory national governmental officials, local community leaders, and top managers at other firms drive corporate proactive and responsive sustainability strategies, which in turn influence market performance. In addition, the findings reveal that financial resource slack strengthens the path between corporate proactive sustainability strategies and market performance, but not the path between corporate responsive sustainability strategies and market performance. Theoretical and practical implications are discussed.