The study investigated the influence of top management team diversity on competitive advantage of insurance companies in Kenya. A cross sectional descriptive survey was applied to research 41 insurance companies and primary data collected from members of their top management teams using a structured questionnaire. Data was analyzed using descriptive and inferential statistics. The study revealed that top management team diversity accounted for 26.8% variation in competitive advantage of insurance companies. Since top management team diversity had a significant and positive effect on competitive advantage, it was useful for competitive advantage of insurance companies in Kenya. The study presented policy and practical implications for practitioners tasked with selection of top executives as it enlightened on designing teams whose members have diverse characteristics to enhance competitive advantage. The research boosted strategy literature by backing the postulations in the upper echelon and resource advantage theories that anchored it. The findings could thus be interpreted and applied in the insurance industry and related settings to boost competitiveness of firms. Since the study conclusions were drawn from analysis of primary data, the researcher recommended that future studies adopt a longitudinal approach to observe relationships among these variables for a longer time.