Carrier-selective　passivating　contacts　in　crystalline　silicon　(c-Si)　solar　cells　have　expanded　from　doped　silicon　films　to　non-silicon　wide-bandgap　materials　to　reduce　parasitic　absorption　and　production　costs.　Titanium　oxide　(TiOx)　has　emerged　as　one　of　the　most　promising　materials　and　has　achieved　high　performance　in　c-Si　solar　cells.　In　this　work,　TiOx　is　explored　as　a　passivation　interlayer　in　hole-selective　contacts　rather　than　conventional　electron-selective　contacts.　Theoretical　calculations　and　experimental　results　demonstrate　that　negative　charges　and　shallow　states　in　TiOx,　derived　from　oxygen　vacancies　(VO),　enhance　surface　passivation　and　assist　hole　tunneling,　respectively.　As　a　strategy　to　modulate　VO,　forming　gas　annealing　is　performed　to　further　improve　hole　selectivity.　By　incorporating　the　TiOx　passivation　interlayer　into　MoOx-based　c-Si　solar　cells,　we　achieve　an　improved　efficiency　and　stability　of　the　device,　with　the　highest　efficiency　of　21.28%.　This　work　advances　the　understanding　of　TiOx　as　a　promising　material　to　enhance　hole　selectivity　for　c-Si　solar　cells.