“Fake news”, or disinformation, is a contemporary phenomenon whose potential to impact on societal and political institutions have been widely documented by scholars. How have governments in Southeast Asia responded to the threat posed by disinformation? To address this, this chapter employs securitisation theory to evaluate political responses in Singapore and Malaysia towards disinformation. It has two key focuses: first, what empirical insight can securitisation theory provide towards explaining the heightened political salience of disinformation in both countries? Second, how have political actors in Singapore and Malaysia securitised disinformation, and what are the subsequent socio-political implications? The securitisation of a political issue gives credence to the urgent need for emergency measures and the mobilisation of resources to resolve a purported existential threat. While disinformation has been evidenced to be a societal problem, this chapter advances that the securitisation of disinformation by the Singapore and Malaysian governments can be construed foremost as politically expedient decisions within the unique socio-political contexts of each country. Specifically, it argues that state actors have sought to instrumentalise disinformation to justify the passing of wide-reaching legislation. In both cases, the passing of these laws has allowed the governments to consolidate political power, increase regulatory oversight and censor criticisms against the state. More broadly, this chapter highlights how authoritarian states have increasingly sought to respond to the global challenge of disinformation by adopting securitisation as a transregional response. The findings problematise the notion of securitisation as an optimal societal response to disinformation, and emphasises the need to guard against consequential encroachments upon media freedom and civil liberties arising from such political responses.