Cognitive principles have been applied in communications and computing networks to improve the transmission efficiency. In the case of wireless networks, the topics are commonly called cognitive radio networks in recent years, while, in the case of wireline networks, the topics could be called cognitive wireline networks. In the case of computing systems, the relevant topics could be called cognitive computing. However, higher spectrum efficiency is usually achieved at the expense of higher energy consumption. In recent years, energy and power efficient designs of communication and computing networks have become more crucial because of the steadily rising energy cost and environmental concerns. Thus, there is an urgent need to address the energy efficiency in such networks. On the other hand, cognitive principles have the potential to improve other aspects of Green IT, such as electromagnetic pollution mitigation, resource and materials reusing, and creating human friendly environments. The first Workshop on Green Cognitive Communications and Computing Networks (GCCCN) is to be held in Toronto, Canada, as a part of IEEE INFOCOM 2014.The purpose of this workshop is to bring together a group of technology researchers from both academia and industry to explore how we can make the computing and communications networks more energy efficient.