This special issue has as its focus the agency of young children in relation to language policy and practice in bi- and multilingual preschools in Finland and Sweden. Studies of language policy in practice in early childhood education and care (ECEC) in these two countries can be particularly relevant even to those in other contexts, because they have been held up as models of progressive policies in terms of early childhood education and multilingual language policy. This article introduces this special issue by comparing and contrasting preschool and language policy in the two countries, describing the common theoretical background of the special issue, introducing the settings of the studies presented in the issue, and highlighting the models of bilingual education in both countries.