Sonic 3D Blast (Japanese: ソニック３Ｄブラスト, Hepburn: Sonikku Surīdī Burasuto), also known as Sonic 3D: Flickies' Island (ソニック３Ｄ フリッキーアイランド, Sonikku Surīdī Furikkī Airando), is a 1996 platform video game developed by Traveller's Tales and Sonic Team, and published by Sega for the Genesis, Saturn, and Windows. Part of the Sonic the Hedgehog series, the game abandons previous Sonic games' side-scrolling style in favor of isometric gameplay, making use of some pre-rendered 3D models converted into sprites. The game features creatures known as Flickies, which first appeared in the 1984 arcade game Flicky. Controlling only Sonic himself, the player's goal is to collect Flickies and carry them to safety, periodically sparring with the series antagonist Dr. Robotnik, who is imprisoning them within robots.

The game was developed alongside another Sonic game for the Sega Saturn, known as Sonic X-treme, which would end up cancelled. While 3D Blast was initially created for the Genesis, which had already been discontinued, Sega also commissioned a port for the Saturn. The Saturn version of 3D Blast was developed as a backup plan in case X-treme could not be released. Both versions of Sonic 3D Blast received mixed reviews from critics, who generally disliked its isometric gameplay but praised its visuals and music. The game was later ported in 1997 to Microsoft Windows computers and released on numerous Sonic themed compilations and digital distribution platforms.