This book constitutes extended, revised and selected papers from the 6th International Conference on Cloud Computing and Services Science, CLOSER 2016, held in Rome, Italy, in April 2016. The 16 papers presented in this volume were carefully reviewed and selected from a total of 123 submissions. The volume also contains two invited papers. CLOSER 2016 focused on the emerging area of cloud computing, inspired by recent advances related to infrastructures, operations, and service availability through global networks. It also studied the influence of service science in this area.