Instagram/Kevin McKidd TV Kevin McKidd responds to Harry Potter casting rumors as Arthur Weasley after Grey's Anatomy exit. May 11, 2026 AceShowbiz - Harry Potter fans have been buzzing after rumors suggested that Kevin McKidd, known for his role on Grey's Anatomy, might be cast as Arthur Weasley in the upcoming HBO series. These rumors gained traction when it was noticed that Gracie Cochrane, who plays Ginny Weasley in the series, began following McKidd on Instagram, sparking speculation among fans.