In this study, the operating environment’s attributes and its influence on the performance of airlines in Southeast Asia are assessed through a comprehensive literature review and performance analysis. As a first step, a Pareto Analysis is performed to assess the capacity contribution of registered airlines in the Southeast Asia region, totalling 65 in 2019. Then, seven of the largest Southeast Asian airlines, representing 80% of total capacity in the region, are taken forward into an in-depth benchmarking and Product and Organisational Architecture (POA) performance analysis. The research pinpoints key differences between Full-Service Carriers and Low-Cost Carriers in the region through a series of 13 metrics applied in the POA. It was found that the region’s FSCs scored better at Product Architecture, which includes convenience, comfort and connectivity, whilst the LCCs strength was in the Organisational Structure component, namely fleet and labour productivity, sales and distribution, and airport attractiveness, especially in the case of AirAsia.