The Arabia Circular Hub Helsinki -project launches a hub aimed at small and medium-sized circular economy businesses. The hub is located in the Arabia industrial district in Helsinki. The purpose of the new physical and virtual operating environment of the Hub is to support the SME business operations, production processes, product innovations, and regional and international RDI (Research, Development, and Innovation) cooperation. The primary target group of the project is small and medium-sized enterprises (SMEs) and startups in the circular economy sector in the Uusimaa region. This target group also includes the regional RDI ecosystem related to the circular economy, such as local universities and development companies. Additionally, the target group includes companies or other organizations already operating in the Arabia neighbourhood near the circular economy hub. Arabia Circular Hub Helsinki will create an active network of participants that promotes the growth and internationalization of SMEs in the sector by strengthening expertise in innovation activities, design, commercialization, and the adoption of new technologies based on the circular economy. The flexible spaces and network structure of the Hub support both inter-company innovation activities and RDI cooperation. Service models that facilitate cooperation will also be developed. The project will be implemented as a cooperation project involving two organizations. Forum Virium Helsinki, as the coordinator, will be responsible for leading the project and, among other things, developing digital solutions, promoting RDI and business cooperation, and international networking. The City of Helsinki, through the Business Helsinki department, will be responsible, among other things, for developing the operational and operator model of the circular economy hub and for measures to promote the business of the target group. The activity of the Arabia Circular Hub Helsinki is fundamentally a driving force, or an initiator of new operations. Therefore, the impact of the project will be visible in the long term in particular. The longer-term goals include promoting the growth and employment opportunities of circular economy businesses in the area, as well as strengthening the competitiveness of the region through new innovation activities, such as the development of production processes and product innovations by companies. Simultaneously, a more efficient exchange of information and new models of cooperation between companies and RDI organizations will facilitate better mutual utilization of data and information. New knowledge to strengthen research infrastructures will also be created. Business ecosystems that are newly interconnected in this way will boost the growth of the entire circular economy sector, thereby revitalising the region's economic structure in the long term. The project supports several regional, national, and international strategies, such as the Smart Specialization Strategy for Helsinki-Uusimaa, the Uusimaa Regional Programme, and the Uusimaa RDI Roadmap, as well as the EU Strategy for the Baltic Sea Region. The project also supports the City of Helsinki's goals to enhance the development of pilot and testing platforms for companies. Furthermore, it addresses the gender equality and sustainable development objectives of the European Regional Development Fund (ERDF).