Sega Technical Institute (STI) was an American video game developer owned by Sega. Founded by the Atari veteran Mark Cerny in 1990, STI sought to combine elite Japanese developers, including the Sonic Team programmer Yuji Naka and his team, with new American talent. STI developed games for Sega Genesis, including several Sonic the Hedgehog games, before it was closed at the end of 1996.

After working in Japan for Sega on games for the Master System, Cerny proposed the creation of a development studio in America, which was approved. When Naka quit Sega after the release of Sonic the Hedgehog, Cerny convinced him to join STI. After completing Sonic the Hedgehog 2 in 1992, STI was divided in two due to friction between the Japanese and American developers: the Japanese developed Sonic the Hedgehog 3 and Sonic & Knuckles before leaving in 1994, while the Americans developed games including Sonic Spinball. The failed development of Sonic X-treme for the Sega Saturn became representative of a culture shift at Sega, and STI closed at the end of 1996.