Dark photons, massive gauge boson carriers of a new U(1)' that kinetically mix with the SM photon, have been proposed in a wide range of BSM models and could serve as our window to the Dark Sector.  If dark photons decay back to the SM with a significant branching fraction, collider searches involving leptonic final states provide promising discovery prospects.  The rich phenomenology, with exotic signatures such as Lepton-Jets, poses unusual search challenges which require us to find innovative handles.  ATLAS has risen to this challenge, with multiple complementary analyses covering large swaths of previously unexplored parameter space, and is building on the successes of its 8TeV dark photon analyses for even wider-reaching 13TeV versions.