Maternal depression and anxiety are potential risk factors to children's language environments and development. Though existing work has examined relations between these constructs, further work is needed accounting for both depression and anxiety and using more direct measures of the home language environment and children's language development. We examined 265 mother-infant dyads (49.6% female, M[subscript age] = 17.03 months) from a large city in the Western United States to explore the relations between self-reports of maternal depression and anxiety and observational indices of the home language environment and expressive language as captured by Language Environment Analysis (LENA) and parent-reported language comprehension and production. Results revealed maternal depressive symptoms to be negatively associated with home language environment and expressive language indices. Maternal anxiety symptoms were found to be negatively associated with children's parent-reported language production. These findings provide further evidence that maternal mental health modulates children's home language environments and expressive language.