The　escalating　consumption　of　fossil　fuels　and　the　worsening　of　environmental　pollution　have　rendered　the　advancement　of　sustainable　clean　energy　conversion　technologies　an　urgent　priority.　Piezo-photocatalytic　technology,　which　integrates　piezoelectric　and　photoexcited　properties,　provides　an　efficient　means　of　converting　chemical　energy　by　utilizing　mechanical　and　solar　energy.　Oxygen　vacancies　(OVs),　as　a　critical　type　of　defect　structure,　play　a　significant　role　in　enhancing　piezo-photocatalytic　performance　by　modifying　the　band　structure,　improving　polarization　effects,　and　providing　additional　active　sites.　This　review　comprehensively　examines　the　formation　methods　and　characterization　techniques　of　OVs,　alongside　their　mechanistic　roles　in　piezo-photocatalytic　technology.　We　discuss　how　OVs　influence　the　band　structure,　dipole　moments,　and　local　electronic　configurations.　Furthermore,　we　summarize　the　applications　of　OVs　in　various　fields,　including　water　pollution　degradation,　hydrogen　production,　nitrogen　fixation,　and　CO2　reduction.　Finally,　we　outline　future　research　directions　for　OVs,　focusing　on　precise　synthesis　methods,　the　development　of　novel　piezoelectric　materials,　enhancement　of　stability,　and　the　investigation　of　interactions　between　OVs　and　other　local　structures.　We　hope　that　this　review　will　provide　valuable　insights　for　the　continued　development　and　application　of　OVs　in　piezo-photocatalysis.　©　2025　The　Royal　Society　of　Chemistry.