Even though Sonic the Hedgehog 2 came out earlier this year, a release date has already been announced for the next movie. Sonic the Hedgehog 3 will be out sooner rather than later.
Sonic the Hedgehog 3 has an official release date of December 20th, 2024. The characters of Sonic, Tails and Knuckles are expected to return to the movie.
The appearance of Dr Robotnik is up in the air as Jim Carrey is taking a break form acting. It might be possible that another villain might be in the movie instead.
Sonic the Hedgehog 2 teased the appearance of Shadow which is likely a sign he will also be in the new movie. More details about the film should be revealed in the foreseeable future.