A bstract A search for CP violation in D 0 → π − π + π 0 decays is reported, using pp collision data collected by the LHCb experiment from 2015 to 2018 corresponding to an integrated luminosity of 6 fb − 1 . An unbinned model-independent approach provides sensitivity to local CP violation within the two-dimensional phase space of the decay. The method is validated using the Cabibbo-favoured channel D 0 → K − π + π 0 and background regions of the signal mode. The results are consistent with CP symmetry in this decay.