The 3rd International Workshop on Community Networks and Bottom-up-Broadband(CNBuB 2014) will be held in October 8, 2014 in Larnaca, Cyprus, co-located with the 10th IEEE WiMob. Community networking, together with the Bottom-up-Broadband initiative, is an emerging model for the Future Internet across Europe and beyond where communities of citizens build, operate and own open IP-based networks, a key infrastructure for individual and collective digital participation. The CNBuB 2014 workshop aims at serving as a meeting point for researchers and practitioners, both from academia and community networks, to discuss state-of-the-art and in-progress research, exchange ideas and share experiences. The workshop will address theoretical and practical challenges of community networks and bottom-up-broadband, including insights from other disciplines that contribute to the socio-technical-economic understanding of the community network operation and growth. To support the growth of community networking and bottom-up-broadband in society, it is necessary to improve the state-of-the-art in design, operation, and evolution of community networks. Towards this objective, the networking and systems research community has the opportunity to contribute with more sustainable, adaptive, scalable, integrated, autonomic solutions.