By　virtue　of　the　high　reliability　of　click　chemistry,　polymers　with　clickable　groups　provide　a　useful　platform　for　the　rapid　synthesis　of　polymer　materials　with　diverse　functionalities　and　architectures.　However,　the　polymerization　of　clickable　vinyl　monomers　with　a　concurrent　regulation　on　tacticity　remains　underdeveloped.　Herein,　we　report　the　successful　development　of　a　stereoselective　cationic　copolymerization　of　C−C　triple　bond-containing　vinyl　ethers　with　simple　alkyl　vinyl　ethers　by　employing　confined　Brønsted　acid　as　catalyst,　which　allows　for　the　synthesis　of　alkyne-functionalized　vinyl　ether　copolymers　with　high　isotacticity　(up　to　90　%　m),　controlled　molecular　weight,　and　variable　content　of　C−C　triple　bonds.　Further　transformation　of　the　pendant　clickable　alkyne　groups　via　thiol-yne　click　reactions　and　copper(I)-catalyzed　alkyne-azide　cycloaddition　reaction　enables　a　modular　access　to　isotactic　polymers　with　various　functional　groups.　©　2024　Wiley-VCH　GmbH.