E-commerce is redefining the landscape of ASEAN economy. Nevertheless, the prospect for a sustainable growth of ASEAN e-commerce would be dismal unless states maintain a clear and predictable legal framework for e-commerce. The primary focus of this research is electronic signature law, one of the most foundational areas in e-commerce legislation. The paper specifically selects Malaysia, Singapore, Thailand and Vietnam for investigation – the four leading ASEAN countries in the rapidly transforming regional e-commerce market. As this paper finds, under the influences of global, regional and comparative practices, these countries have developed their own domestic electronic signature regulation through various legislative and administrative measures. The paper demonstrates a trend of regulatory convergence developed in ASEAN states governing the use of electronic signatures, and explains the features of this trend.