The major purpose of this study was to examine the potential mediating role of perceived motor skill competence on relationships between actual ball skills and children’s physical activity (PA) and PA enjoyment. A total of 294 students (Mage = 10.96 ± 0.76; 51.7% boys) from three elementary schools completed validated questionnaires assessing their perceived competence, self-reported PA, and PA enjoyment. Students’ actual ball skills (i.e., basketball, overhand throwing, striking) were measured by PE MetricsTM. Correlation analyses showed positive relationships among the study variables (rs ranging from 0.12 to 0.56). The structural equation modeling (SEM) analyses demonstrated that the mediation model produces a goodness-of-fit to the data: χ2/df = 52.03/32; CFI = 0.96; NFI = 0.90; IFI = 0.96, RMSEA = 0.05, SRMR = 0.04. Path coefficients suggested that actual ball skill competence was strongly associated with perceived competence (β = 0.36, p < 0.01), which in turn significantly predicted PA (β = 0.29, p < 0.01) and PA enjoyment (β = 0.35, p < 0.01). The findings highlight that ball skills significantly impact students’ perceived competence, positively and indirectly affecting their PA and PA enjoyment. This study provides empirical evidence that recommends intervention strategies aimed at fostering elementary school students’ PA and PA enjoyment.