  We study how neutrino oscillations could probe the existence of ultralight
bosonic dark matter. Three distinct signatures on neutrino oscillations are
identified, depending on the mass of the dark matter and the specific
experimental setup. These are time modulation signals, oscillation probability
distortions due to fast modulations, and fast varying matter effects. We
provide all the necessary information to perform a bottom-up, model-independent
experimental analysis to probe such scenarios. Using the future DUNE experiment
as an example, we estimate its sensitivity to ultralight scalar dark matter.
Our results could be easily used by any other oscillation experiment.
