We report herein a quantitative end‐capping chemistry for the efficient synthesis of monotelechelic hyperbranched polyethylenes containing various ω‐end functionalities by quenching Pd‐diimine catalyzed ethylene “living” polymerization with styrene derivatives. This chemistry utilizes the unique reaction of styrene derivatives with cationic Pd‐diimine species to form stable π‐benzyl intermediate complexes, which are inactive for ethylene polymerization. In the synthesis, “living” hyperbranched polyethylene chains were grown with a Pd‐diimine catalyst. Subsequent end‐quenching of the “living” chains with three styrene derivatives renders narrowly distributed telechelic hyperbranched polyethylenes containing different functional ω‐terminal groups.