Critical thinking is often described as purposeful, reflective judgment, encompassing both skills and disposition components. Are critical thinking and fluid intelligence distinct capabilities, or do they rely on similar cognitive processes? Extensive research indicates that executive functions, which govern the cognitive control of complex, goal-oriented behavior, play pivotal roles in both critical thinking and fluid intelligence. This current study delves into the degree of overlap between critical thinking and fluid intelligence, exploring how three frequently cited executive functions—updating, inhibition, and shifting—predict each of these faculties and their overlap. Data were gathered from a sample of 232 university students (142 female; Mage = 19.70, SD age = 1.22) on measures of critical thinking skills, critical thinking dispositions, fluid intelligence and executive functions. The findings reveal that fluid intelligence exhibits a significant association with both critical thinking skills (r = 0.62) and critical thinking dispositions (r = 0.31). Furthermore, the functions of updating and inhibition significantly contribute to both critical thinking skills and fluid intelligence, jointly explaining 85 % of their common variance. However, executive functions did not emerge as significant predictors of critical thinking dispositions. These results contribute to our deeper comprehension of human intelligence by elucidating the distinctions and associations between critical thinking and fluid intelligence, while shedding light on their underlying cognitive mechanisms.