On the 7th of November 2024, C40 held a global City-Business Climate Alliance (CBCA) Workshop at the Smart City Expo World Congress in Barcelona, Spain. We brought together climate and economic development leads from 17 cities, along with sustainability leaders from businesses and NGOs for a 1-day workshop on city-business climate collaboration. This Summary Report gives insight to the 7 city case studies and 6 key takeaways from the workshop.