This paper aims to identify and compare the key features of Unmanned Aerial Vehicles regulations in Thailand and Australia on the issue of classification of unmanned aircraft. The study adopted a documentary research approach, both from the regulatory documents and related researches. The results of the research revealed that Thailand and Australia use the same criteria to classify unmanned aircraft. Those are the objective of use and the weight. However, there are still substantial differences in detail, for instance, risk assessment, airworthiness, licensing, and a variety of unmanned aerial applications, especially for commercial use. The research findings imply several conclusions identified as the most essential and it will be necessary to adopt legislative changes to comply with the recommendations of the International Civil Aviation Organization.