Only Murders in the Building Season 6 Cast Adds 20 New Stars for London Mystery

Hulu’s favorite true-crime podcasters are packing their trench coats and heading across the pond, and they are not traveling light. Only Murders in the Building Season 6 has officially expanded its recurring guest star roster to an absolutely massive 20 actors. The Hulu comedy is trading the cozy elevators of the Arconia for the dreary streets of London, England, and the casting department clearly went on a shopping spree at the British Academy of Film and Television Arts. With heavy hitters like David Tennant, Jodie Whittaker, and Nicola Coughlan leading the pack, Charles, Oliver, and Mabel are about to face an international crime scene that is crowded in the best way possible.

A Transatlantic Mystery at the Arconia Gates

The Season 5 finale left us all staring at our screens wondering how a murder at the gates of a New York apartment complex could possibly lead to a British vacation. Showrunner John Hoffman has teased that the upcoming 10-episode arc centers around Tina Fey’s infamous character, Cinda Canning, who met a grim fate but left behind plenty of baggage tied to England.

Not happy about the trio leaving New York, but if anyone can make a transatlantic flight look stylish, it is Selena Gomez, Steve Martin, and Martin Short. The production has officially moved base to the United Kingdom, turning the upcoming season into a full-blown British invasion.

The 20 New Faces Joining the Mystery

Trying to keep track of this roster requires a spreadsheet, but the talent is undeniable. Bridgerton fans can celebrate because Nicola Coughlan and Simone Ashley are both checking in. If that is not enough star power, the series is pulling off a minor sci-fi miracle by casting two former Time Lords, David Tennant and Jodie Whittaker, in the exact same season. The Doctor Who crossover we never expected is happening in a Hulu comedy.

The massive 20-person guest star lineup also features an elite selection of UK comedic royalty and dramatic icons:

• The Comedy Legends: Richard Ayoade, Jennifer Saunders, Jamie Demetriou, and Sharon Horgan.

• The Dramatic Heavyweights: Jim Broadbent, Derek Jacobi, Martin Freeman, and Kathryn Hunter.

• The Mainstays: Adrian Lukis, Geri Halliwell-Horner, Anjana Vasan, Jane Horrocks, Lesley Nicol, Sean Teale, Amar Chadha-Patel, and Rhea Norwood.

Can the Trio Survive a Crowded Room?

As a critic watching this show evolve from a small, intimate satire about lonely Upper West Side neighbors into a massive, star-studded phenomenon, it is easy to wonder if the central dynamic will get lost in the noise. The sheer volume of actors could easily overwhelm a lesser comedy. However, the brilliance of this series has always been its ability to treat its guest stars like highly specific puzzle pieces rather than flashy distractions.

We already know that Da'Vine Joy Randolph’s Detective Donna Williams is making the trip over to keep an eye on the amateur sleuths, alongside Michael Cyril Creighton's Howard Morris. Adding 20 more eccentric personalities into the mix gives the writers an endless supply of red herrings and suspicious motives.

Whether David Tennant is playing a eccentric theater rival to Oliver, or Nicola Coughlan is playing a tech-savvy podcaster trying to steal Mabel's thunder, the comedic potential is incredibly high. The series is taking a massive gamble by abandoning its titular building, but leaning into the absurdly deep bench of British talent is exactly how you keep a long-running comedy feeling fresh.

Which of the 20 new guest stars are you most excited to see cross paths with Charles, Oliver, and Mabel? Head over to our comment section or find us on social media to share your theories on who the killer might be.