Alkali‐metal　doped　perovskite　oxides　have　emerged　as　promising　materials　due　to　their　unique　properties　and　broad　applications　in　various　fields,　including　photovoltaics　and　catalysis.　Understanding　the　complex　interplay　between　alkali　metal　doping,　structural　modifications,　and　their　impact　on　performance　remains　a　crucial　challenge.　In　this　study,　this　challenge　is　addressed　by　investigating　the　synthesis　and　properties　of　Rb‐doped　perovskite　oxides.　These　results　reveal　that　the　doping　of　Rb　into　perovskite　oxides　function　as　a　structural　modifier　in　the　as‐synthesized　samples　and　during　the　oxygen　evolution　reaction　(OER)　as　well.　Electron　microscopy　and　first‐principles　calculations　confirm　the　enrichment　of　Rb　on　the　surface　of　the　as‐synthesized　sample.　Further　investigations　into　the　electrocatalytic　reaction　revealed　that　the　Rb‐doped　perovskite　underwent　drastic　restructuring　with　Rb　leaching　and　formation　of　strontium　oxide.