Effective airport economic oversight plays a crucial role in promoting efficiency, fairness, and competition within the aviation industry, ultimately benefiting airlines, passengers, end users, and the economy as a whole. The International Civil Aviation Organisation (ICAO) provides guidance to States and airport operators on regulatory mechanisms and governance on airport economics. Its core values on non-discrimination, cost-relatedness, transparency, and consultation with users are essential because airports often operate as monopolies or oligopolies within their regions, which can lead to market power abuses if left unchecked. Thailand presents an interesting case study in relation to economic oversight of a state enterprise operator. The Airports of Thailand Public Company Limited (AOT), corporatised from the state-owned entity in 2002, with the government retaining a 70% shareholding, operates six out of seven international airports in Thailand. This chapter explores how Thailand implements ICAO economic oversight framework into its national regulations and practices. Particular attention is paid to the law and policy applying to the state enterprise airport operator. Hence, it analyses how the AOT’s state enterprise status affects governance in both aeronautical and non-aeronautical activities, and how the abovementioned core values and airport performance management mechanisms, enshrined in ICAO documents, are translated into domestic practice, especially in case of airport charges.