The actress, who plays Arya Stark, confesses she will find it "really weird" when the hit show is not part of her life anymore.
Williams, 21, who has grown up playing Arya Stark, told Sky News that fans just don't want it to end but for her "it's the right time" for it to finish."I don't think anyone is going to be satisfied [when it ends]. I don't think anyone wants it to end but I'm really proud of this final season," she said.
Williams admitted: "It's going to be really weird when it's done and every day it's a step closer to it not being a part of my life anymore."
She said she hoped to be invited to any party thrown by co-star Kit Harington, after he told that he was considering an event to mark the end, but said that instead it would "probably be me and my flatmate, and he's going to say 'well done', and I'm going to go 'thanks, bedtime'."
Williams spoke to students at Birmingham University about her new app, Daisie, which is "a platform for artists to be able to discover one another and collaborate with up-and-coming projects they may have".
Williams wants the app to make it easier for young people to break into an "industry that's so fickle" and which doesn't reward talent fairly.