He was raised as a Catholic, but has since left the faith. He has an older sister, Sarah, and a younger sister, Hannah. His mother was an art teacher, while his father worked at an employment agency.

Scott was born in Dublin, Ireland, on 21 October 1976, the son of Nora and Jim Scott. Scott has received various other awards, including the Laurence Olivier Award for Outstanding Achievement in an Affiliate Theatre for his role in A Girl in a Car with a Man at the Royal Court Theatre. He won further acclaim playing the lead role of Garry Essendine in a 2019 stage production of Present Laughter at The Old Vic, for which he won the Laurence Olivier Award for Best Actor in a Leading Role in a Play. Scott is also known for playing the priest on the second series of Fleabag, receiving a nomination for the Golden Globe Award for Best Supporting Actor – Series, Miniseries or Television Film and winning the Critics' Choice Television Award for Best Supporting Actor in a Comedy Series. He achieved widespread recognition for the breakthrough role of Jim Moriarty in the BBC series Sherlock, for which he won the BAFTA Television Award for Best Supporting Actor. Andrew Scott (born 21 October 1976) is an Irish actor.