The purpose of CONCUR 2018, the 29^th International Conference on Concurrency Theory, is to bring together researchers, developers, and students in order to advance the theory of concurrency, and promote its applications. In 2018, CONCUR takes place as part of CONFESTA, which is the umbrella event comprising the joint international 2018 meetings CONCUR, FORMATS, QEST, and SETTA, alongside with several workshops and tutorials. The topics covered are Theory, Formal Modelling, Verification, Performance Evaluation and Engineering of concurrent, timed, cyber-physical, and other systems.