We tested the association between early childcare attendance in the first three years of life and child development at age 3.5 years in the French context, where early childcare is subsidized. In the ELFE (Étude Longitudinale Français depuis l'Enfance) birth cohort study set in metropolitan France, children’s development was reported by parents at age 3.5 years (n = 11,033) via the Child Development Inventory (CDI) questionnaire. CDI scores were transformed into a development quotient (DQ), with a DQ < 90 corresponding to possible and a DQ < 85 corresponding to a probable developmental delay. Inverse probability weighted multivariable regression models were used to analyse whether early childcare in the first three years of life (centre-based, childminder, informal or parental care) was associated to development delay. Compared to children in exclusive parental care, those in centre-based childcare (CBC) or with a childminder prior to school entry were significantly less likely to experience possible (OR = 0.56, [95% CI = 0.51–0.61] for CBC and OR = 0.77, [95% CI = 0.72–0.83] for childminder attendance) and probable developmental delay (OR = 0.62, [0.58–0.67] for CBC and OR = 0.80 [0.76–0.83] for childminder). Informal childcare attendance was not significantly associated with children’s possible nor probable developmental delay ((OR = 0.97, [0.84–1.12]) and (OR = 0.97, [0.82–1.15]), respectively). Conclusions: Overall, our findings add to the existing scientific literature, showing that in the French context, where childcare can start as early as 3 months of age, early childcare attendance can contribute to child’s development.