Background and objectives: The role of schools in the spread of SARS-CoV-2 infections in the community remains controversial. The objective of our study was to describe the epidemiology of SARS-CoV-2 infections in different pediatric age groups during the first two months of the fall back-to-school period, in the context of increasing viral transmission in France. Methods: Weekly epidemiological data provided by Santé Publique France and the Ministry of National Education were analyzed according to the age groups defined by the different school levels. Weeks (W) 34–42 were included in the analysis. Results: The PCR positivity rate and incidence rate increased in all age groups during the study period, in an age-dependent manner. In W42, with adults serving as the reference group, the risk ratio for a positive PCR test was 0.46 [95% CI: 0.44–0.49] for children aged 0–5 years and 0.69 [0.68–0.70] for those aged 6–17 years. Similarly, the incidence rate ratio was 0.09 [0.08–0.09], 0.31 [0.30–0.32], 0.64 [0.63–0.66], and 1.07 [1.05–1.10] for children aged 0–5 years, 6–10 years, 11–14 years, and 15–17 years, respectively. Children and adolescents accounted for 1.9% of newly hospitalized patients between W34 and W42, and for 1.3% of new intensive care admissions. No deaths were observed. Among infected children and adolescents, the percentage of asymptomatic individuals was 57% at W34 and 48% at W42. The number of school closures remained low, at less than 1% throughout the study period. The number of confirmed cases among school staff was consistent with the data measured in the general population. Conclusion: in the context of increasing viral transmission in the population, the spread among children and adolescents remained lower than that observed among adults, despite keeping schools open. However, the impact was age-dependent, with data in high schools close to those observed in adults.