Sonic the Hedgehog 3 is an upcoming action-adventure comedy film based on the video game series published by Sega. The sequel to Sonic the Hedgehog (2020) and Sonic the Hedgehog 2 (2022), it is directed by Jeff Fowler from a screenplay by Pat Casey, Josh Miller, and John Whittington, based on a story by Casey and Miller. Jim Carrey, Ben Schwartz, Colleen O'Shaughnessey, Natasha Rothwell, Shemar Moore, James Marsden, Tika Sumpter, and Idris Elba reprise their roles, with Krysten Ritter and Keanu Reeves joining the cast. In the film, Sonic, Tails, and Knuckles ally with Dr. Robotnik to defeat a new enemy, Shadow the Hedgehog.

Plans for a third Sonic the Hedgehog film were announced in February 2022 during ViacomCBS's investor event before the release of the second film. Due to the 2023 SAG-AFTRA strike, filming for animated characters began in July 2023 in Surrey, England, while filming with physical actors began in November of that year in London, with production concluding by March 2024. The film draws inspiration from the video games Sonic Adventure 2 (2001) and Shadow the Hedgehog (2005), with many elements of Shadow's character in the games adapted for the screen in a "fan faithful" rendition.

Sonic the Hedgehog 3 is scheduled to be theatrically released by Paramount Pictures in the United States on December 20, 2024.