The Firefly cast have secured the rights to Firefly, and plan to turn it into an animated series with the original cast voicing. https://deadline.com/2026/03/nathan-fillion-firefly-animated-series-development-1236754122/
Nathan Fillion Says ‘Firefly’ Animated Series In Development With Co-Stars Set To Reprise Roles; Concept Art Revealed

Nathan Fillion says 'Firefly' animated series is in development with costars to voice their original roles. Concept art revealed.

Deadline
@GossiTheDog hmm. I feel like Alan Tudyk's original statement still applies here. there shouldn't be a Firefly sequel because at this point literally nothing could live up to expectations.
@gsuberland @GossiTheDog have to agree. While I’d love more, I fear the mythos is far too big to ever feel adequate.
@petrillic @gsuberland @GossiTheDog I think that's why it being animated rather than live action is a good idea. It gives it space to breathe and be its own thing, plus it means we can ignore the fact that the cast are like 20 years older (and that Ron Glass is sadly no longer with us).
@Myphatself @hedders @petrillic @gsuberland @GossiTheDog my theory is the cast just like each other and want to get back together, and economics are second
@travisfw @Myphatself @hedders @petrillic @gsuberland @GossiTheDog The suits would never believe it, but that probably gives it more room to be something special.
@petrillic @gsuberland @GossiTheDog Have Denis Villeneuve direct it and it'll be fine.