From Sonic Retro
December 7 (
- 1994 — Sonic the Hedgehog - Remix, an album remixing the songs of Sonic the Hedgehog CD, is released on CD in Japan.
- 1995 — Issue #3 of the comic mini-series Sonic the Hedgehog's Buddy Tails is released in North America.
- 1999 — Sonic the Hedgehog Pocket Adventure is released for the Neo Geo Pocket Color in North America.
- 2003 — "Uchuu Kara no Kyouhaku", the 36th episode of Sonic X, airs in Japan.
- 2006 — Sonic the Hedgehog is released on the Wii Virtual Console in Australia.
- 2007 — Sonic Rivals 2 is released for the PlayStation Portable in Europe.
- 2011 — History of Sonic Music 20th Anniversary Edition, a compilation album, is released on CD in Japan. Sonic Select Book Four, a trade paperback, is released in North America. Sonic & Sega All-Stars Racing is released for Windows PCs in Russia. Sonic Generations is made available for digital download on the PlayStation Store in North America, Europe, and Australia.
- 2012 — Sonic & All-Stars Racing Transformed is released for the PlayStation Vita in Europe and Australia.
- 2018 — Super Smash Bros. Ultimate is released for the Nintendo Switch worldwide, featuring Sonic as a guest fighter.
- 2022 — Sonic Frontiers Original Soundtrack Stillness & Motion, an album, is released on CD in Japan and digitally worldwide. Issue #55 of the Sonic the Hedgehog comic series by IDW Publishing is released in North America.