Harry Osborn appears in the Ultimate Spider-Man cartoon series, voiced by Matt Lanter. This version is one of Peter Parker's best friends, Norman Osborn's disappointment of a son, and the series' first incarnation of Venom. In the first season, Harry is badly injured by Klaw while trying to protect Mary Jane Watson from the Frightful Four. Harry is then jealous of Peter's "new friends" (Sam Alexander, Luke Cage, Danny Rand and Ava Ayala) so he throws a huge party that is crashed by the Venom organism. After thesymbiote's defeat, Harry captures a fragment. Harry bonds with the organism to be the "Black Suit Spidey" in an attempt to one-up Spider-Man and even wins over J. Jonah Jameson's trust. But the symbiote's personality takes over Harry and transforms into Venom until Spider-Man electrocutes and disintegrates the organism off Harry. But some of the symbiote managed to survive within Harry. Harry later has no memory of being Venom, and Spider-Man tried to help him without exposing his identity as Venom's host to the web-slinger's teammates. Eventually, Spider-Man's Anti-Venom supposedly cured Harry of Venom. But during the Green Goblin's rampage on the S.H.I.E.L.D.Helicarrier, the Venom symbiote is revealed to have survived within Harry and comes into form after the Goblin's provoking. But he eventually manages to shake off the Venom suit with electricity. In the second season, Harry watches the Green Goblin kidnaps Peter to be forcibly transformed into Carnage. Although Harry stops Carnage and saves Peter by rebonding with the symbiote, Venom feeds on Harry's dark desires, attacking to kill the Goblin until Peter manages to convince Harry to get rid of the symbiote to which S.H.I.E.L.D. manages to capture to ensure no more harm. In the third season, Harry is glad that his cured father is no longer a Green Goblin and feels good to have his father back into a good person.
- Harry seems to dislike Spider-Man because his father seemed more interested in things about Spider-Man than being with him.
- Harry is Venom in this universe, rather than Eddie Brock or Mac Gargan.
- Harry's hatred of Spider-Man yet friendship with Peter Parker mirrors his film counterpart.
- Harry Osborn is voiced by Matt Lanter.