The amount of time children spend in front of screens has increased in recent years in France, as evidenced by various repeated cross-sectional surveys. However, there are no longitudinal data available at the national level, particularly for children under 3 years of age. Using data from the Elfe cohort, we describe screen time—both total and by screen type—for children followed at ages 2, 3½, and 5½ years. We also highlight disparities based on the family’s region of residence, migration history and background, the mother’s educational level, and the child’s gender. After weighting the data, daily screen time averaged 56 minutes (95% confidence interval: [55–58]) at age 2, 1 hour and 20 minutes [1 hour 18 minutes–1 hour 22 minutes] at age 3.5, and 1 hour and 34 minutes [1 hour 32 minutes–1 hour 36 minutes] at age 5.5. These durations were positively correlated (0.50 between 2 and 3.5 years; 0.67 between 3.5 and 5.5 years), demonstrating individual persistence in usage over time. Overall, screen time was higher among families with immigrant backgrounds or where the mother had a low level of education. Regional disparities were also observed. Finally, while no difference between boys and girls was observed at age 2, boys used screens 10 minutes longer than girls at age 5.5. This study provides the first nationwide, longitudinal description of the time young children spend in front of screens. It will help better identify families and contexts where screen time exceeds recommendations.