As climate change becomes an increasingly urgent global issue, social media has emerged as a powerful platform for disseminating climate-related information and shaping public perceptions and responses. Among university students, who are active users of platforms such as TikTok, Instagram, YouTube, and Facebook, social media exposure may facilitate the acquisition of climate-related information, influence environmental beliefs, and elicit emotional reactions such as worry, all of which may ultimately shape mitigation behaviour. However, the psychological associations between social media exposure and climate change engagement have received limited attention, particularly in the Malaysian context. This study explored the relationships between social media exposure, climate change beliefs, self-efficacy, and climate-related worry, and how these variables were associated with three types of mitigation behaviour: accommodating behaviour (e.g., seeking climate information), promotional behaviour (e.g., sharing posts or supporting climate policies), and proactive behaviour (e.g., adopting low-carbon lifestyle practices). A cross-sectional online survey was conducted with 384 Malaysian university students, using self-reported questionnaire items to assess all psychological and behavioural constructs. The strength and direction of associations among all variables were examined. This study provides insights into the cognitive and emotional correlates of climate engagement among the digital generation.