​‘Young Sherlock’: All about the cast, plot, and where to watch; a complete guide

The highly anticipated period mystery ‘Young Sherlock’ is now available for streaming. Starring Hero Fiennes Tiffin, the series offers a different look at the well-known detective long before he became the sharp, confident figure people know from classic stories. The series is inspired by Andrew Lane’s 2010 novel ‘Young Sherlock Holmes.’
Here’s the complete watch guide for ‘Young Sherlock.’

Set in the 1870s, ‘Young Sherlock’ follows 19-year-old Sherlock at Oxford University. The Impulsive young man finds himself stuck in a murder case and begins investigating to clear his name. As the case unfolds, it reveals a larger conspiracy that shapes his future and introduces his first encounter with James Moriarty.

Season 1 of Young Sherlock premiered on Wednesday, March 4, 2026, on Amazon Prime Video. All the episodes were dropped at once. The season has 8 episodes.
The episodes are titled:

Episode 1: The Case of the Missing Scrolls

Episode 2: The Case of the Burnt Photograph

Episode 3: The Case of the Unarmed Man

Episode 4: The Case of the Missing Button

Episode 5: The Case of Young Sherlock Holmes

Episode 6: The Case of the Killing Jar

Episode 7: The Case of the Two Corners

Episode 8: The Case of Beatrice Holmes

The cast is a mix of Gen Z talent and veteran actors. Along with Hero Fiennes Tiffin as Sherlock, the show features Dónal Finn as Moriarty and a strong supporting cast. Colin Firth plays Sir Bucephalus Hodge. Joseph Fiennes and Natascha McElhone appear as Sherlock’s parents. Max Irons takes on the role of Mycroft Holmes, while Zine Tseng plays Princess Gulun Shou’an.

Matthew Parkhill created the series, whose filming took place across several locations in the UK and Spain. Bristol was used to recreate Oxford, while other scenes were shot in Cardiff, London, and Somerset. In Spain, parts of the series were filmed in Jerez and Seville.