An unprecedented C(8)-H bond allylation of quinoline with allyl carbonate and allyl alcohol catalyzed by Cp*Co(III) using a traceless directing group via β-oxygen and β-hydroxy elimination is described. This site-selective allylation reaction proceeds smoothly with various functional group tolerance including quinoxaline and phenanthridine. Under the nonoxidative reaction conditions, the difference in selectivity between Rh(III) and Co(III), which proceeds through β-hydride and β-hydroxy elimination using allyl alcohol, is shown for the first time.