 Justin Hartley portrays Oliver Queen , a billionaire who left Star City to live in Metropolis . While in Metropolis , Oliver masquerades at night as a costumed vigilante , named " Green Arrow " by Lois . Oliver leaves Metropolis in season six , after destroying one of Lex 's secret 33 @.@ 1 facilities , where Lex experiments on meteor @-@ infected individuals against their will , but he returns in season eight to search for Clark , after the latter goes missing when his Fortress of Solitude is destroyed . Hartley was a recurring guest in the sixth and seventh seasons , but became a series regular in season eight . 
