Herein,　a　high　figure　of　merit　(ZT)　of　approximate　to　1.7　at　823　K　is　reported　in　p-type　polycrystalline　Cd-doped　SnSe　by　combining　cation　vacancies　and　localized-lattice　engineering.　It　is　observed　that　the　introduction　of　Cd　atoms　in　SnSe　lattice　induce　Sn　vacancies,　which　act　as　p-type　dopants.　A　combination　of　facile　solvothermal　synthesis　and　fast　spark　plasma　sintering　technique　boosts　the　Sn　vacancy　to　a　high　level　of　approximate　to　2.9%,　which　results　in　an　optimum　hole　concentration　of　approximate　to　2.6　x　10(19)　cm(-3)　and　an　improved　power　factor　of　approximate　to　6.9　mu　W　cm(-1)　K-2.　Simultaneously,　a　low　thermal　conductivity　of　approximate　to　0.33　W　m(-1)　K-1　is　achieved　by　effective　phonon　scattering　at　localized　crystal　imperfections,　as　observed　by　detailed　structural　characterizations.　Density　functional　theory　calculations　reveal　that　the　role　of　Cd　atoms　in　the　SnSe　lattice　is　to　reduce　the　formation　energy　of　Sn　vacancies,　which　in　turn　lower　the　Fermi　level　down　into　the　valence　bands,　generating　holes.　This　work　explores　the　fundamental　Cd-doping　mechanisms　at　the　nanoscale　in　a　SnSe　matrix　and　demonstrates　vacancy　and　localized-lattice　engineering　as　an　effective　approach　to　boosting　thermoelectric　performance.　The　work　provides　an　avenue　in　achieving　high-performance　thermoelectric　properties　of　materials.