In Kenya, the insurance industry is one of the major sectors of the economy. The government has identified this sector as one of the components needed to stimulate and support economic growth. However, the sector faces numerous challenges. According to AIC Capital Ltd, the main challenges facing the insurance sector in Kenya are the low penetration and the high level of competition. The average level of insurance penetration in Kenya during the period 2013-2022 stood at less than 3% in an industry with approximately 56 firms. To increase penetration levels and enhance competitiveness, the insurance firms in Kenya have introduced operational excellence strategies. The aim of this study was to determine the effect of operational excellence strategy on firm performance in Insurance Companies in Kenya. Operational excellence strategy was indicated using customer-centric strategy, innovation, agility, and developmental capabilities. Firm performance was indicated using the growth of market share, growth in customer base, and penetration level. The study was anchored by the dynamic capabilities theory, the theory of economic development, and the Deming theory. The study used a descriptive research design. The target population for the study were all licensed insurance firms in Kenya. The study used a census sampling technique and sampled 44 firms. The unit of observation in the study was the managers in charge of corporate strategy and firm performance. The study sampled one hundred and sixteen managers working at the respective insurance firms. The study data was collected using closed-ended questionnaires. The study data were analysed using descriptive and inferential analysis. The study established that the firms used customer-centric strategies because the firms' activities were focused on the customers' needs and expectations. The study established that the firm was continuously innovating its products, product mix, and services to better serve the customers. The study found that the firm has measures in place that were meant to adapt it to changing circumstances, including dynamic capabilities to detect external threats, competitive, responsive techniques, continuous adjustment and adaptations, and new strategic initiatives that rapidly respond to changing circumstances. These are indicators of agility. The study established that the insurance firms had various development capabilities, including research, training programs, increasing expertise and knowledge acquisitions. The results of the inferential analysis indicated that customer-centric, innovation, agility and development capabilities strategies had positive and statistically significant effects on the performance of the insurance firms surveyed in this study.