Which Sega studio is best known for developing the Sonic series?

The Sega studio best known for developing the Sonic series is Sonic Team.

Sonic Team is Sega’s development division most closely associated with the main Sonic the Hedgehog games. The group’s early core included programmer Yuji Naka, artist Naoto Ohshima, and designer Hirokazu Yasuhara, who created the original Sonic game for the Sega Genesis in 1991. That debut helped establish Sonic as Sega’s mascot and a major rival to Nintendo’s Mario.

The name Sonic Team became associated with more than platform games. During the 1990s, the group also developed Saturn titles such as Nights into Dreams and Burning Rangers. It returned to Sonic in a major way with Sonic Adventure, the 1998 Dreamcast game that moved the series into 3D and became the console’s best-selling title.

Other studios have worked on Sonic games, including Sega Technical Institute, Traveller’s Tales, Dimps, and later external developers. That does not make them the canonical answer here: Sonic Team is the studio identity most strongly linked to the franchise, even though development responsibilities have shifted across Sega’s divisions over time.