The emergence of new social media platforms such as Twitter has revolutionized the means of communication and dissemination, providing unprecedented networking avenues for immediate news spread. But this ease has also increased the spread of fake news which is a concern faced by many nations including Nigeria. Fake news simply deceives, suppresses facts relevant to political life or spreads information intended only to harm, having a direct impact on national security. For Nigeria, a country rich in ethnic, religious and political prejudice, the effects of fake news can go as far as inciting violence, destroying the social fabric or even causing instability. This study investigated the prevalence, characteristics and consequences of fake news on Twitter during critical events in Nigeria, using a qualitative methodology to understand how false information is spread and what potential threat it poses to national security. The paper uses secondary data from the extant literature and Twitter-Archive for investigating how fake news spreads, consequently shaping public opinion, damaging social solidarity and threatening national security. It lists the top drivers of misinformation in Nigeria – including poor media literacy, political divisiveness and over-dependence on social media as sources of news. It also puts forward solutions to address the risks posed by this kind of content on Twitter, including government legislation, fact-checking mechanisms, media literacy initiatives and consumer take-backs. The study contributes to a deeper understanding of the complex relationship between Twitter, fake news, and national security in Nigeria, highlighting the urgent need for proactive measures to protect the country’s stability and well-being.