Brendan is the son of renowned Scottish actor James McAvoy and accomplished British actress Anne-Marie Duff. James McAvoy, his father, has gained widespread recognition for his roles in popular films such as Atonement, The Last King of Scotland, and Split. Before they became widely known, Brendan’s parents first crossed paths while portraying an on-screen romantic pair in the UK television series Shameless back in 2003. The couple eventually tied the knot in 2006, marking a significant chapter in their personal lives. However, their marriage came to an end in 2016. As for Brendan, he remains the first and only child of his parents, holding a unique place in their lives despite their eventual separation.