This volume constitutes the refereed post-conference proceedings of the Third IFIP TC 5 DCITDRR International Conference on Information Technology in Disaster Risk Reduction, ITDRR 2018, held as part of the 24th IFIP World Computer Congress, WCC 2018,  in Poznan, Poland, in September 2018.The 12 revised full papers presented were carefully reviewed and selected from 32 submissions. The papers focus on various aspects and challenges of coping with disaster risk reduction. The main topics include areas such as natural disasters, big data, cloud computing, Internet of Things, mobile computing, emergency management, disaster information processing, and disaster risk assessment and management.