The antichrist is an accursed being in the vein of Judas. He does have free will, but it’s limited free will in that he can only sin and will never be able to come to Christ.
It would make sense that he would have free will. How could he become the AntiChrist if not for that free will? Even Judas (although some might argue that he was fated to have betrayed Jesus) made a decision, no?
DISCLAIMER: Catholic Answers has turned over the archive to Catholic-Questions.org and no longer owns, manages, or moderates the forums. For additional apologetics resources please visit www.catholic.com.