She attended the American School in England.
She learned the American accent in her childhood, and lived in the U.S. for eight years to perfect it.
She grew up with family near Ascot, in Berkshire, UK. She has an older brother as well as a younger brother and sister. Luddington is married to fellow actor Matthew Alan. They have a daughter Hayden who was born in 2017 and a son Lucas who was born in 2020.
She was obsessed with Ricki Lake as a child, recreating episodes with her younger siblings.