Background: Social media has become deeply integrated into students’ academic and social lives, raising concerns regarding its potential impacts on cognitive functioning. Excessive social media use may contribute to attentional difficulties, and distorted thinking patterns. 
Aim: This study aimed to explore the association between social media addiction and cognitive distortion among university students. 
Methods: A descriptive correlational design was used among a convenience sample of 146 nursing students at Riyadh Elm University, Saudi Arabia. Data were collected electronically using the Social Media Addiction Scale–Student Form (SMAS-SF) and the Cognitive Assessment Questionnaire (CAQ). Both instruments demonstrated excellent internal consistency in the current study, with Cronbach’s alpha coefficients of 0.926 and 0.928, respectively. 
Results: The mean social media dependence score was 3.085 ± 0.790, while the mean cognitive distortion score was 2.886 ± 0.807. A statistically significant moderate positive correlation was found between social media dependence and cognitive distortion (r = 0.561, 95% CI: 0.439–0.663, p < 0.001). Cognitive distortion also differed significantly according to daily social media use (p = 0.048). Simple linear regression showed that social media dependence significantly predicted cognitive distortion (β = 0.561, B = 0.573, p < 0.001), explaining 31.5% of the variance in cognitive distortion scores (R² = 0.315). 
Conclusion: Higher levels of social media dependence were significantly associated with greater cognitive distortion among nursing students. These findings highlight the importance of promoting healthy digital-use behaviors and increasing awareness of the potential cognitive effects of excessive social media engagement.