The Aspen Center for Physics has accepted our proposal for a summer workshop in 2018 on the Dynamics of the Milky Way System for the Era of Gaia. Thanks to superb co-organizers Sarah Loebman, Robyn Sanderson, Hans-Walter Rix, Nitya Kallivayalil, and Juna Kollmeier. Our workshop will occur 2018 Aug 26 – Sep 16, and will focus on observational analysis and theoretical modeling of stellar dynamics of the entire Milky Way system, from stars in the disk and bulge to the satellite dwarf galaxies, stellar streams, and stars throughout the halo, as we enter the era of the incredible Gaia satellite mission. We aim to bring together observers, modelers, and simulators, to discuss (1) how to analyze this wealth of high-precision dynamics data and (2) how to develop accurate, cosmologically informed models to interpret them. The overarching goals are galactic archaeology, to understand the full 3D formation history of the entire Milky Way system, and near-field cosmology, to use stellar dynamics to measure the distribution and test the nature of dark matter.