Utilization of 4-dibenzocyclooctynol (DIBO) as an initiator for the ring-opening polymerization of ε-caprolactone yields well-defined, high molecular weight poly(ε-caprolactone) end functionalized with DIBO (DIBO–PCL). Nanofibers bearing reactive DIBO groups were generated via electrospinning and functionalized post-fabrication with azide-tethered molecules.