We propose, for the first time, the potential of beyond the standard model opportunities at the ProtoDUNE experiment in the context of dark matter physics. We explore various experimental signatures at the cosmic frontier, arising in boosted dark matter scenarios, i.e., inelastic scattering of a relativistic dark matter particle often created by the annihilation of its heavier component which usually constitutes the dominant relic density. Although signal features are unique enough to isolate signal events from potential backgrounds, vetoing an enormous amount of cosmic background is rather challenging as the detectors are located on the ground. Nevertheless, we argue, with a careful estimate, that such backgrounds can be well under control via performing dedicated analyses after data acquisition. We then discuss some phenomenological studies which can be achieved with the ProtoDUNE detectors, employing a dark photon scenario as our benchmark dark-sector model.