This study utilized multilevel modeling to examine the student characteristics (gender and age) and school factors (private vs. public school, urban vs. rural school, socioeconomic status, curricular organization, resources, activities, and equipment) associated with individual and between-school differences in the verbal, numerical, and figural intelligence test scores of 7,189 students in Grades 4-9 in the Kingdom of Saudi Arabia. Regarding student characteristics, results showed no substantial gender differences in the 3 intelligence subtests, whereas age accounted for 0.01%-0.06% of the individual differences in subtest performance. School factors accounted for 57.2%-71.6% of the differences in mean intelligence scores across schools. Moreover, 16.3% (figural) to 19.5% (verbal) of the variance was conditioned by different school experiences. Children in public schools achieved higher scores in all subtests, and a higher number of core, extra, and special courses consistently predicted higher scores. These findings extend the view that factors from the educational system are important correlates of intelligence, though they may vary across countries.