This workshop program is focused on the theory and detection of dark matter at the high mass and large size frontiers, which we broadly define as “mega dark matter”. The program of topics include cosmological production of mega dark matter, the theory of mega dark matter interactions, and mega dark matter discovery using both traditional underground dark matter detectors and novel astroparticle methods. By gathering experts with complementary expertise in astronomy, particle theory, astroparticle experiments, and cosmology, we aim to accelerate the search for mega dark matter.