Thea Dearden Queen (born January 21, 1995), also (unofficially) known as Thea Dearden Merlyn, is the daughter of Malcolm Merlyn and the late Moira Queen, the legal daughter of the late Robert Queen (though treated unquestionably as his daughter throughout his life), the ex-step-daughter of Walter Steele, the maternal younger half-sister of Oliver Queen, the paternal younger half-sister of the late Tommy Merlyn and the aunt of William Clayton. Thea is also the ex-girlfriend of Roy Harper. After learning how to fight from Malcolm, Thea became a vigilante and member of Team Arrow using her brother's nickname for her, Speedy, as her code-name.