Limestone　(calcite)　calcined　clay　cement　(LC3)　is　a　promising　low-CO2　binder,　but　the　low　activity　of　calcite　cannot　compensate　the　reduction　in　clinker　factor,　resulting　in　low　one-day　strength　and　limiting　its　broad　applications.　As　recent　carbon　capture　and　utilization　technologies　allow　scalable　production　of　vaterite,　a　more　reactive　CaCO3　polymorph,　we　overcome　the　challenge　by　introducing　vaterite　calcined　clay　cement　(VC3),　inspired　by　the　vaterite-calcite　phase　change.　In　the　present　study,　VC3　exhibits　higher　compressive　strengths　and　faster　hydration　than　LC3.　Compared　to　hydrated　LC3,　hydrated　VC3　exhibits　increased　amount　of　hemi-　and　mono-carboaluminate　formation　and　decreased　amount　of　strätlingite　formation.　With　gypsum　adjustment,　the　1-day　strength　of　VC3　is　higher　than　that　of　pure　cement　reference.　VC3,　a　low-CO2　binder,　presents　great　potential　as　a　host　of　the　metastable　CaCO3　for　carbon　storage　and　utilization　and　as　an　enabler　of　carbon　capture　at　gigaton　scales.　©　2023　Elsevier　Ltd