Trivia

Nephew of actors Ralph Fiennes and Joseph Fiennes.

Director David Yates stated in an interview that he hired Fiennes Tiffin to portray the young Lord Voldemort/Tom Riddle in Harry Potter and the Half-Blood Prince (2009) because of his resemblance to his uncle, actor Ralph Fiennes (who portrayed Voldemort/Tom Riddle as an adult in the series' films) but not specifically because he was the actor's nephew. He liked the dark, haunted quality about the young actor.

Son of Martha Fiennes, a director, writer, and producer, and George Tiffin, a director, novelist, and cameraman.

Resides in London, England.

Is one of three children. He has an older brother, Titan Nathaniel, born 26 August 1995 and a younger sister, Mercy Jini Willow, born 15 October 2001.

He is the face of Ferragamo by Salvatore Ferragamo.

Signed to Storm Models modeling agency.

His paternal grandparents were John Tiffin, a television producer for 60 Minutes, and Wendy Ewer, an advertising copywriter. Wendy was originally from Philadelphia, Pennsylvania. His maternal grandparents were Mark Twisleton-Wykeham-Fiennes, a farmer and photographer, and Jennifer Anne Mary Alleyne Lash, a writer. Many of his recent maternal ancestors lived in India, and his grandmother's parents were born in Bengal and Madras, respectively. His uncle Ralph has said that the surname Fiennes is of Norman origin.

Hero Fiennes Tiffin has appeared in projects alongside both of his uncles. He starred with Ralph Fiennes in Harry Potter and the Half-Blood Prince, where Fiennes Tiffin played the young Tom Riddle and his uncle portrayed Lord Voldemort. He later worked with his other uncle, Joseph Fiennes, in Young Sherlock, playing a young Sherlock Holmes while Joseph Fiennes took on the role of Silas Holmes, Sherlock's father.

Auditioned for multiple roles in various Netflix series, Stranger Things (2016), and movies The Hate U Give (2018) and Dunkirk (2017) but failed to land any of the roles.