The main purpose of this study was to analyze the relationship between physical fitness and academic achievement from multiple perspectives by linking data from the National Physical Fitness and Exercise Survey, and the National Assessment of Educational Attainment and Progress, targeting 1,213 6th grade elementary school students. Additionally, we examined the basic exercise, learning, and lifestyle factors related to the characteristics of physical fitness and academic achievement in a composite manner. The main results were as follows:<br> 　1) Although a significant positive correlation was observed between physical fitness and academic achievement, the degree of association was low.<br> 　2) There were significant differences in the average number of correct responses to the achievement test depending on the children's physical fitness level. Children with higher physical fitness levels tended to have higher academic achievement in all items. However, children in physical fitness assessment group E had significantly lower academic achievement scores, suggesting that the children with high physical fitness tended to have higher academic achievement.<br> 　3) Multiple regression analysis was conducted to examine the influence of lifestyle on both physical fitness and academic achievement. This revealed that 3 items – exercise time on weekdays and weekends and homework effort – were significantly related to physical fitness, 5 items – screen time on weekdays and weekends, homework effort, study preparation and review, and reading time on weekdays – were significantly related to academic achievement.<br> 　The present results have revealed the relationship between physical fitness and academic achievement in upper elementary school students, as well as the characteristics of the combined relationship of basic habits to both.