|Sega Midwest Studio|
Sega Midwest Studio, also known as Sega Midwest Development Division was based in the Chicago, Illinois suburb of Northbrook. When it was closed in January 1995, artists and programmers were offered transfers to Sega offices in other parts of the country.
|Sega Development Studios|
|Japan R&D; 1982-1983|
|Sega Research and Development|
|Japan R&D; 1984-1988|
|Japan R&D; 1988 - 1990|
| Sega R&DD1 | Sega R&DD2 | Sega R&DD3 | Sega R&DD4 | Sega R&DD5 | R&DD6 | Sega R&DD7 | Sega R&DD8|
|Japan AM; 1990 - 2000-ish|
|"Arcade" R&D||"Consumer" R&D|
|Sega AM1 | Sega AM2 | Sega AM3 | Sega AM4 | Sega AM5||| Sega AM9 | Sega AM10? | Sega AM11|
|Japan AM; 2000-ish - 2004-ish|
|WOW Entertainment | Sega AM2 | Hitmaker | Amusement Vision | Sega Rosso | Smilebit | Overworks | Sonic Team | United Game Artists | Sega Mechatronics|
|Japan; 2004 onwards(?)|
|Sega WOW | Sega AM2 | Sonic Team | Sega Sports Design | Ryu ga Gotoku Studio | AM Ishoku Team
First CS R&D | Second CS R&D | Third CS R&D
|Japan non-AM, demerged, and defunct|
|Puyo Puyo Sega | Sega Networks | ???
Demerged: Sonic! Software Planning | Nextech | SIMS | ???
|Three Rings Design | ???|
|The Creative Assembly | Sports Interactive | Hardlight | Relic Entertainment|
|Sega of China|
|Sega Away Team|