This article covers precise syntheses of well-defined chain-end and in-chain functionalized polymers, multi-functionalized polymers with a definite number of functional groups, star-branched and graft polymers by recently developed methodologies using specially designed 1,1-diphenylethylene (DPE) derivatives. The DPE derivatives include various substituted DPE derivatives with functional groups and their derivatives, DPE-functionalized DPE derivatives, and well-defined DPE-functionalized macromonomers. The synthetic utility and importance of these DPE derivatives are described via such polymer syntheses.