Underwent brain surgery in 2012 to treat a pituitary tumour.
Underwent surgery to repair a retinal detachment aged 9, following an accident in a swimming pool.
He uses his maternal grandfather's name as his stage name because he found another actor was using his birth name (Stephen Thorpe).
Became a father for the first time at age 35 when now estranged wife Claire Foy gave birth to their daughter Ivy Rose Moore (b. March 2015).
He and his wife, Claire Foy, have both played a King and Queen of the same family. Stephen played King Edward VIII in Wallis & Edward (2005) and Claire played Queen Elizabeth II (Edward's niece) in The Crown (2016).
Was nominated for 2006 Drama Desk Award - Outstanding Featured Actor in a Play for his role as Irwin in The History Boys.
He is the son of a telecommunications engineer (father) and hospital dietitian-turned-art therapist (mother). He has an older brother who works as an engineer.
Graduated from Guildhall School of Music and Drama in 1999. He was awarded the Gold Medal.
Although born in London he was brought up in Hertfordshire and educated at Berkhamsted School.
At one time he lived in the East Village of Manhattan with his Italian girlfriend Ra, who was a graduate student at Columbia University.