Research Findings: Multiple factors likely influence the language development of young children growing up in low-income homes, potentially including stressors experienced by parents. Here, we ask: (1) What is the association between stress (i.e., economic hardship and parenting stress) and toddlers' language development? and (2) Does number of hours spent in nonparental childcare moderate the relation between stress (i.e., economic hardship and parenting stress) and toddlers' language development? Participants were 100 mother-child dyads participating in a longitudinal study when children were 0 to 24 months of age. Results showed a significant interaction between hours spent in nonparental childcare and parenting stress when predicting language growth: when parenting stress was high, childcare hours showed a positive relation with language growth; on the contrary, when parenting stress was low, the relation between childcare hours and language growth showed a negative tendency. Conversely, economic hardship did not predict language growth. Practice or Policy: These findings suggest that one potential approach to facilitate language development for low-income children is to help high-stress families secure early years childcare. Furthermore, programs to reduce parenting stress may help to promote children's language growth, especially when families are not using nonparental care.