The Global Urban Monitoring Framework (UMF) is one of several international frameworks for monitoring progress in urban sustainable development with indicators from the Sustainable Development Goals (SDGs) and other frameworks such as the City Prosperity Index (CPI). Like the SDGs, many of the 77 UMF indicators lack data, and reporting is largely conducted at a national rather than a local level. Citizen science represents one important data source to address these data gaps at a more local level. Hence, the aim of this paper is to undertake a systematic review of where citizen science could potentially provide data for the UMF indicators using secondary data from citizen science projects. The results showed that citizen science data are already contributing and could contribute to 52 UMF indicators (~68%). Integrating citizen science into urban decision-making is essential so that local communities are at the heart of creating safe, inclusive, resilient, and sustainable cities.