He is loved by many following how talented he is as an actor and they have been wanting to know more about him, especially about his parental life to know more about his children.
James McAvoy children: Brendan McAvoy
James is the father of one child, a son who has been identified as Brendan McAvoy. Brendan is a celebrity kid who was born to the actor and his first wife Anne-Marie Duff – an English actress and narrator who is an accomplished theatre actress and has been nominated for a Laurence Olivier Award.
He was born to his parents in 2010, hence he is currently at the age of 12. There is little information about him since his parents have decided to keep most of his personal information away from the general public.
His parents were married for a decade. They tied the knot on November 11, 2006, but on May 13, 2016, the couple jointly announced their decision to divorce.
Source: Ghanafuo.com