Voldemort wants to kill Harry Potter because of a prophecy that foretold that a child born at the end of July would have the power to defeat him. Voldemort chose to target Harry, believing Harry to be his equal and the greatest threat to his power. This choice made the prophecy self-fulfilling. Additionally, Voldemort wants to eliminate Harry because Harry's parents, James and Lily Potter, had defied Voldemort multiple times, and they stood in the way of his attempt to kill the boy. When Voldemort tried to kill baby Harry, Lily Potter sacrificed herself to protect her son, creating a powerful magical protection for Harry. This protection caused Voldemort's killing curse to backfire, leading to Voldemort's initial downfall and making Harry "The Boy Who Lived." Voldemort also inadvertently created a Horcrux in Harry by putting a part of his soul inside him during the attack, tying their fates together further. Finally, Voldemort's desire to kill Harry is also driven by his need to prove he is the most powerful wizard and to prevent anyone who could threaten his rule from rising against him. Voldemort does not understand love or sacrifice, and Harry's survival is partly due to these forces, which Voldemort sees as weaknesses. In summary, Voldemort wants to kill Harry because he sees him as a prophesied rival destined to defeat him, a threat made real by Voldemort's own actions, and because killing Harry would solidify his own power and eliminate a dangerous enemy.
