Although children’s participation and agency are highly prioritized in early childhood education for sustainability, both researchers and educators have paid little attention to this topic. This paper explores how the revised preschool curriculum Lpfö2018 in Sweden addresses education for sustainability (EfS) with regards to children’s participation and agency. A sociocultural perspective on agency combined with a holistic view of sustainability was used, while a critical content analysis was conducted to investigate major changes in the curriculum in relation to both EfS and children’s participation and agency. Findings show that the curriculum Lpfö2018 has explicitly introduced the concept of sustainability from a holistic perspective, integrating environmental, social, and economic dimensions. Children are recognized as competent beings who can actively participate in and influence their learning. Moreover, the notion of transformative learning has been observed in the curriculum, which emphasizes changes in the ways children think, act, and learn in relation to sustainability.