Besides being responsible for making household names out of Daniel Radcliffe, Rupert Grint, and Emma Watson, the "Harry Potter" franchise was a treasure trove of U.K. talent that either roamed or attempted to invade the halls of Hogwarts School for Witchcraft and Wizardry. And yet, plenty of actors turned down the "Harry Potter" franchise. One major name that never made it past the gates was Scottish star, Tilda Swinton. When picking through the stellar cast that would teach these heroes-in-the-making, Swinton's name was considered for the part of Divination professor Sybill Trelawney, who debuted in "Harry Potter and the Prisoner of Azkaban" (aka the best "Harry Potter" film in the franchise), which instead went to Emma Thompson. Swinton, however, declined the role for a very valid and personal reason.

Speaking to Scot Magazine, Swinton revealed she was against a core element of the franchise — the school that Potter and...