This independent side event of the UN Food Systems Summit launches a new citizen science initiative reaching out to famers and food consumers around the world to take part in advancing knowledge that can accelerate agroecological transitions. Examples of citizen science approaches used in agroecology and related domains will be showcased followed by discussion of what we can learn about how to make citizen science inclusive and effective. We will look at critiques of the use of big data in agri-food systems transformation and explore how to ensure that this initiative will increase the agency of smallholder farmers and farm workers, women, indigenous peoples and food consumers from all backgrounds. Finally, we will have an interactive session to gather ideas and views from session participants on their priorities for what the initiative should focus on. A series of national and regional events will follow to consolidate the focus of the initiative and then put citizen science into action in support of agroecological transitions.