Jim Carrey Expected to Star in 'Grinch' Sequel

Jim Carrey is going green once again ... because he's expected to star in a sequel to "How the Grinch Stole Christmas," TMZ has confirmed.

The follow-up to the 2000 holiday blockbuster is in the works at Universal ... and Jim will be going back to Whoville with director Ron Howard and producer Brian Grazer.

Jim's live-action film made a ton of money when it came out 26 years ago ... and became a staple on the holiday movie rotation.

For the moment ... it's unclear what other OG cast members might be returning ... and that includes Cindy Lou Who actress Taylor Momsen -- who ditched acting for a successful music career. Still, fans went freaking nuts when she and Jim reunited last year at the Rock & Roll Hall of Fame Induction Ceremony. So, it could happen!

It's wild Jim's coming back ... he's been against doing a sequel for years ... probably because the make-up process was so brutal for him. But ... CGI has come a long way, so maybe that's no longer an issue.

Bottom line ... Jim's heart grew a few sizes about this sequel ... and the dump truck of money he's getting most likely helped.