To prepare today's students confidently for the future, it is necessary to equip them with different skills. Among these skills, 21st-century skills and computational thinking skills are crucial. While there are views suggesting that computational thinking skills contribute to the development of 21st-century skills, the relationship between these two skill sets remains uncertain. This study aims to examine the relationship between middle school students' computational thinking skills and 21st-century skills. In other words, it investigates whether there is a relationship between students' computational thinking skills and 21st-century skills and whether computational thinking skills serve as a meaningful predictor of 21st-century skills. Conducted with the participation of 328 eighth-grade students using a correlational survey design, this research employed the "Computational Thinking Scale" and the "21st-Century Skills Scale" to collect data, which were then analyzed using descriptive statistics, Pearson correlation coefficient analysis, and multiple linear regression analysis. The research findings indicate that students have a high perception of both computational thinking and 21st-century skills. Moreover, a positive and significant relationship was found between computational thinking skills and 21st-century skills. The study also reveals that the abstraction, decomposition, algorithmic thinking, evaluation, and generalization skills that constitute computational thinking significantly predict 21st-century skills, explaining 72% of the variance in 21st-century skills. When examining the standardized regression coefficients, it can be concluded that evaluation, algorithmic thinking, generalization, decomposition, and abstraction skills are significant predictors of 21st-century skills in order of importance.