This is the proceedings of the Ninth International Symposium on Exotic Nuclei EXON-2018, 10-15 September, Petrozavodsk, Russia. The first symposium took place 27 years ago in 1991 in Foros (Crimea), the later symposiums were held on Baikal Lake, in Peterhof, Khanty-Mansiysk, Sochi, Vladivostok, Kaliningrad and Kazan. The organizers of the Symposium were the five largest scientific centers of heavy-ion physics - JINR (Dubna), the RIKEN Research Center (Japan), the GANIL National Center (France), the GSI Helmholtz Centre for Heavy Ion Research (Germany), the National Superconducting Cyclotron Laboratory (Michigan, USA). The main topics are: properties of light exotic nuclei, synthesis and properties of superheavy elements, rare processes and decays, experimental facilities and future projects.