The Indonesia–Malaysia–Thailand Growth Triangle (IMT-GT) comprises five priority economic corridors that are key geographic areas for subregional economic cooperation under the IMT-GT. A review and assessment of these economic corridors was conducted to evaluate the status of infrastructure connectivity, impacts on cross-border trade, and implications for value chains. This Thailand country report focuses on the three economic corridors that directly connect to southern Thailand in the context of the country’s development strategies. The report discusses how the existing corridors could be reconfigured and proposes the route for a new corridor that will involve additional provinces in southern Thailand.