Raising knowledge and awareness about alternative financing and business models for large-scale implementation of Nature-based Solutions (NbS) in European cities has been one of the major impacts of Horizon 2020 project Connecting Nature. The cities of Genk (BE), Glasgow (UK) and Poznan (PL) are applying this knowledge to instigate long-term systemic change within their own public administration bodies and organisations. Drawing lessons from this process, this policy brief presents how the three cities are securing financing to support NbS implementation, the main challenges and enablers to financing NbS at the city-level that are relevant to policy-makers, and the findings of Connecting Nature's three-year study on NbS finance mechanisms and funds.