A cable barrier delineator for selective attachment on roadway barrier cable systems that utilize steel cables between posts as a vehicle safety barrier along highways. The cable barrier delineator is a rectangular one-piece cable attachment having double sided reflective insert surfaces with a split apertured mounting tab for cable engagement extending therefrom. An attachment tab retainment tie stays selectively positioned through apertures in said mounting tabs, stabilizes and prevent unauthorized removal once installed and secured on the cable.