Young students have raised their voices in debates on what action for sustainable development (SD) is necessary. Nevertheless, research that gives voice to 10 to 13-year-olds while looking into SD issues in all their complexity of interrelated environmental, social, and socio-economic perspectives, is scarce. This study aims to give voice to these youngsters, asking them directly how they suggest they can contribute to SD. Building on the concepts of action and SD, this qualitative study reports on early adolescents' own suggestions for action. Participants suggested direct, indirect, individual, and collective actions both in the private and public sphere. Their actions targeted SD issues with interconnections between areas concerning the planet, peace, people, partnership, and to some extent also prosperity. We compare our results with findings of earlier studies to further the discussion on how young people feel they can and want to contribute to SD.