Abraham Ayomide Oluwaseun2024-05-152024-05-152022-12M.Schttps://repository.lcu.edu.ng/handle/123456789/83Constant use of social media by citizens has played a significant role in fostering both positive and negative relationship among people of all ages. Also, engagement in citizen journalism through the use of social media has a broad impact on the security of every nation. This study, therefore, investigated The Polytechnic Ibadan students’ social media use, engagement in citizen journalism and security challenges in Nigeria. The study adopted a descriptive survey research design. Multi- stage sampling technique was used to select 403 respondents. A validated instrument named “Citizen Journalism Social Media Questionnaire” (CiJoSoMeQ) was used for data collection and data were analysed using descriptive and inferential statistics. Findings revealed that students of The Polytechnic Ibadan made use of eight popular social media platforms and were mostly engaged in online discussion to a large extent through the use of Facebook (93.5%) , (Weighted mean = 1.40) Whatsapp (93.1%), Instagram (86.1%) and Twitter (61.3%). Again, students involvement in citizen journalism was very high (weighted mean 1.85), and majority of the students had good perception on the use of social media in discussing national security challenges (weighted mean 2.83). There was no significant difference (r = 0.053, p<0.05; r = 0.941; p<0.05) in the level of engagement in online discussion and perception of social media use in discussing security challenges in Nigeria. Thus, the study concluded that The Polytechnic Ibadan Students’ social media use, engagement in citizen journalism does not have any influence on security challenges in Nigeria. The study recommends that the use of other social media platforms should be accessed and recommends that important security information should be disseminated on social media in order to avoid misuse and spreading false security news. Key Words: Use, Engagement, Social Media, Citizen Journalism, Security Challenges. Word Count: 265enThesis