In　recent　decades,　the　environmental　protection　and　long-term　sustainability　have　become　the　focus　of　attention　due　to　the　increasing　pollution　generated　by　the　intense　industrialization.　To　overcome　these　issues,　environmental　catalysis　has　increasingly　been　used　to　solve　the　negative　impact　of　pollutants　emission　on　the　global　environment　and　human　health.　Supported　platinum-metal-group　(PGM)　materials　are　commonly　utilized　as　the　state-of-the-art　catalysts　to　eliminate　gaseous　pollutants　but　large　quantities　of　PGMs　are　required.　By　comparison,　single-atom　site　catalysts　(SACs)　have　attracted　much　attention　in　catalysis　owing　to　their　100%　atom　efficiency　and　unique　catalytic　performances　towards　various　reactions.　Over　the　past　decade,　we　have　witnessed　burgeoning　interests　of　SACs　in　heterogeneous　catalysis.　However,　to　the　best　of　our　knowledge,　the　systematic　summary　and　analysis　of　SACs　in　catalytic　elimination　of　environmental　pollutants　has　not　yet　been　reported.　In　this　paper,　we　summarize　and　discuss　the　environmental　catalysis　applications　of　SACs.　Particular　focus　was　paid　to　automotive　and　stationary　emission　control,　including　model　reaction　(CO　oxidation,　NO　reduction　and　hydrocarbon　oxidation),　overall　reaction　(three-way　catalytic　and　diesel　oxidation　reaction),　elimination　of　volatile　organic　compounds　(formaldehyde,　benzene,　and　toluene),　and　removal/decomposition　of　other　pollutants　(Hg(0)and　SO3).　Perspectives　related　to　further　challenges,　directions　and　design　strategies　of　single-atom　site　catalysts　in　environmental　catalysis　were　also　provided.