As evinced by multiple astrophysical measurements, a large fraction of the matter in the Universe is in the form of a dark, non-baryonic component. If dark matter interacts weakly with Standard Model particles it could be produced at the LHC, escaping the ATLAS detector and thus leaving a signature of large missing transverse momentum. If this interaction is mediated by a kinematically accessible mediator, then that mediator can also give rise to a dijet resonance signature. The latest results of these dijet resonance searches are presented, and their limitations and future prospects discussed.