SampTA2017 is the 12th International Conference on Sampling Theory and Applications. It is a biennial interdisciplinary international conference for mathematicians, engineers, and applied scientists, with previous meetings in Riga (Latvia), Aveiro (Portugal), Loen (Norway), Orlando (U.S.A.), Strobl (Austria), Samsun (Turkey), Thessaloniki (Greece), Marseilles (France), Singapore, Bremen (Germany), and Washington (USA). The main purpose of SampTA is to exchange recent advances in sampling theory and to explore new trends and directions in the related areas of application. The conference focuses on such fields as signal and image processing, compressed sensing, coding theory, control theory, computational neuroscience, information theory, real and complex analysis, and applied, computational, and classical harmonic analysis. SampTA 2017 will feature 9 plenary speakers, 9 special sessions, 9 general sessions, and a poster session. Paper submissions on any of the above topics are welcomed.