Well-defined norbornene-functional poly(carbonate)s were prepared by ring-opening polymerization and utilized as multireactive polymeric scaffolds in a range of postpolymerization modifications. The norbornene-functional handles were shown to undergo facile reaction with azides via a 1,3-dipolar cycloaddition, tetrazines in the inverse electron demand Diels-Alder reaction and thiols via radical thiol-ene coupling. Furthermore, the above-mentioned chemistries were demonstrated in a sequential one-pot, three-step modification reaction illustrating the potential of these polymers as scaffolds to access multifunctionalized materials in an undemanding manner.