Recently, issues related to fake news, misinformation, and disinformation have been argued about and noted by many countries. To effectively tackle the threats posed by fake news and false information, a number of European and Asian countries have conducted and implemented various policies aimed at prohibiting the so-called fake news. Similarly, in recent years, Taiwan has faced severe threats posed by fake news, misinformation, and disinformation, and therefore, the relevant issues have been widely discussed and debated by policy-making elites and nationals of Taiwan. By employing the Copenhagen School's theory of securitization, this research aims to understand the so-called fake news phenomena in Taiwan and explain how the Tsai Ing-wen administration perceives fake news, disinformation, and the external influence of China as existential threats to Taiwan's national security. The data analysis focuses on speeches, interviews, and radio addresses given by Taiwanese officials, and President Tsai in particular. Besides, in order to fully understand the securitization of disinformation in Taiwan, especially the measures taken by the Tsai Ing-wen administration, official documents and reports published by the Taiwanese government are examined and analyzed. Research argues and illustrates that the securitization of disinformation in Taiwan should be comprehended and discussed in light of the specific social and political contexts. Additionally, two significant events occurred in 2018-namely, the suicide of a Taiwanese diplomat in Osaka, Japan, and the November local elections-forced the ruling administration to prioritize disinformation and anti-disinformation. In the name of countering disinformation and China's external influence, since 2018 various policies have been prompted, introduced, and implemented, including the amendments to national legislation, the institutionalization of anti-disinformation within government structures, and the enhancement of international cooperation on anti-disinformation.