Meet the Cast of Guy Ritchie’s Young Sherlock: Your Guide to the Season’s Key Players

Well, it looks like Prime Video wants to give us Sherlock Holmes like we've never seen him before: as a messy 19-year-old, running wild through Victorian England with Guy Ritchie holding the camera steady (and probably breaking a lot of furniture in the process). Whether you are still recovering from Robert Downey Jr.'s punchy-tweedy detective or just waiting for the next must-binge British mystery, 'Young Sherlock' is gearing up to be a pretty wild swing.

What's the Deal With 'Young Sherlock'?

So here’s the pitch: this isn’t your grandad’s pipe-smoking Sherlock, and it isn’t the studious sidekick version either. Guy Ritchie (yes, the director who blows things up in stylish ways) is directing and executive producing the early life of Sherlock Holmes. This show doesn’t adapt any one Arthur Conan Doyle story—instead it lifts from Andrew Lane’s 'Young Sherlock Holmes' series, digging into what exactly turned Sherlock into the legendary, world-weary genius we all know.

We’re talking 1870s Oxford, scandal, globe-trotting, and a Sherlock who’s already gotten himself in trouble with the law—so, plenty of room for Ritchie’s knack for mayhem. According to the official synopsis, Sherlock is a 'disgraced young man – raw and unfiltered' whose first murder case both imperils his freedom and launches him into a sprawling conspiracy. Expect emotional drama with extra explosions, and Ritchie’s signature chaotic energy.

Who's Playing Who?

The most impressive flex here might honestly be the cast list. You’ve got staple British actors, some genuinely interesting wild cards, and a few faces you probably know but won’t recognize in Victorian getup. Here’s how it shakes out:

• Hero Fiennes Tiffin: Sherlock Holmes, here as a reckless 19-year-old with a sharp mind and a lot of baggage. He's definitely not the composed, violin-playing Holmes you're probably picturing.
• Zine Tseng: Princess Gulun Shou'an, a young Chinese royal who’s both a scholar and a martial artist. If that sounds unexpected, that’s because it is.
• Dónal Finn: James Moriarty. Yep, Sherlock’s forever-nemesis is already lurking in his teenage orbit.
• Joseph Fiennes: Silas Holmes, Sherlock’s father, who’s more on the 'adventurer' end of the spectrum than 'quiet pipe-reader'.
• Natascha McElhone: Cordelia Holmes, the equally unconventional (and artistic) mother of Sherlock and Mycroft.
• Colin Firth: Sir Bucephalus Hodge—a name that’s hard to say with a straight face, and that’s about all we know for now.
• Max Irons: Mycroft Holmes, Sherlock’s older (and usually more sensible) brother.
• Numan Acar, Ravi Aujla, Holly Cattle, Simon Delaney, Adam James, Rachel Shelley, Ian Midlane: A strong supporting crew, ranging from medical professionals to police detectives to characters whose bios haven’t been released but are sure to either help or annoy Sherlock at critical moments.

There’s definitely pedigree here—veteran actors alongside up-and-comers. It’s a risky blend, but there’s enough talent to pull off something genuinely engaging if the scripts don’t get too tangled up in their own cleverness.

Production Shakedown

Guy Ritchie will be directing the first two episodes and is also executive producing, clearly putting his stamp on the tone. Matthew Parkhill is running the show—he also wrote the scripts and carries the 'showrunner' badge. There’s a solid executive-producing lineup (Dhana Gilbert, Marc Resteghini, Simon Maxwell, Ivan Atkinson, Simon Kelton, Colin Wilson), along with co-EPs Harriet Creelman and Steve Thompson. If you care about 'where did they shoot this?'—it’s a globe-hopper: mainly Bristol in the UK, plus locations across Spain (Jerez, Cádiz, Seville) and Cardiff, Wales. Expect pretty landscapes and potentially an impressively expensive costume budget.

When and Where Can You Watch?

Prime Video is skipping the weekly rollout headache on this one. 'Young Sherlock' lands with all 8 episodes on March 4, 2026, so you can binge the whole thing in one sitting—presumably with plenty of tea and possibly a side of existential dread.

The Quick Version

If you want a rundown you can pitch to your group chat, here it is:

Title: Young Sherlock
Platform: Prime Video (worldwide)
Release Date: March 4, 2026
Episodes: 8 (all dropping at once)
Director: Guy Ritchie (first 2 eps + exec producing)
Main Cast: Hero Fiennes Tiffin (Sherlock), Dónal Finn (Moriarty), Zine Tseng (Princess Gulun Shou'an), Max Irons (Mycroft), Joseph Fiennes, Natascha McElhone, Colin Firth
Premise: Teenage Sherlock’s first big case, with trouble at Oxford, a world-spanning plot, family drama, and, naturally, his arch-rival Moriarty.
Showrunner: Matthew Parkhill
Shooting Locations: UK, Spain, Wales

Final Thoughts

So, is this another unnecessary franchise extension, or a genuinely fresh take on a character that, frankly, could use a few more rough edges? I guess we’ll have an answer in spring 2026. Until then: cue the dramatic music, polish your pocket watch, and get ready to see Sherlock try (and probably fail) to behave like a normal 19-year-old.

‘Young Sherlock’ drops March 4, 2026 on Prime Video.