A Ghoul Investigator Training Academy (喰種捜査官養成学校, Gūru Sōsakan Yōsei Gakkō), usually shortened to Academy (アカデミー, Akademī), is an institution devoted to training future Ghoul Investigators.
In Tokyo, there exist at least seven Academies.
Under normal circumstances, only graduates of the Academy are permitted to become ghoul investigators and begin their careers as Rank 2 Investigators. Rare exceptions do exist, and begin their careers as Rank 3 Investigators.
The Academy offers a two-year curriculum that covers numerous subjects in preparing the graduates for work as a full-fledged investigator. Exact details about the training and lessons provided by the Academy are classified, and may not be disclosed to non-graduates. It is known that they learn about the Ghoul Countermeasures Law, ghoul biology, investigative procedures, quinque use, and intense physical training to prepare them for live combat.
Ghoul Investigators occasionally visit the Academy as guest instructors to lecture cadets about their work and equipment in the field. They also present reasons for joining the federal law enforcement agency when they graduate.
A special honors curriculum exists that permits students to graduate within one year.
Attached to each Academy, there exists an Academy Junior School (アカデミージュニアスクール, Akademī Junia Sukūru). These are educational facilities for children and adolescents, and their students are called Academy juniors (アカデミージュニア, Akademī Junia) or Academy cadets (アカデミー候補生, Akademī Kouhosei). They serve as a boarding school for children in the care of the CCG – in particular children that lost their parents to ghouls – but are also open to children from the general public, and are known to be cheap in tuition.
In extracurricular activities, juniors can train or learn martial arts to prepare them for a career as ghoul investigators.
After graduating, juniors can take any career path like graduates from any other high school, but they are encouraged to enroll at the Academy and become ghoul investigators.
- Kasuka Mado (formerly)
- Yukinori Shinohara (Second Academy, formerly)
- Goumasa Tokage (Second Academy)
- Uchino (Second Academy)
- Hanbee Abara - 5th Academy Junior
- Koutarou Amon - Academy (Graduate, Valedictorian)
- Taishi Fura - 4th Academy
- Take Hirako - 3rd Academy Junior
- Kuramoto Itou - 6th Academy Junior
- Shizuku Kawakami - 2nd Academy Junior
- Takeomi Kuroiwa - 7th Academy Junior (Honors Curriculum) 
- Akira Mado - Academy (Graduate, Valedictorian)
- Shinji Michibata - 3rd Academy Junior
- Miyuki Mikage - 4th Academy Junior
- Tooru Mutsuki - 2nd Academy Junior
- Keijin Nakarai - 1st Academy Junior
- Yasuhito Nezu - 6th Academy Junior
- Ginshi Shirazu - 7th Academy Junior
- Juuzou Suzuya - 2nd Academy Junior
- Seidou Takizawa - Academy (Graduate, Salutatorian)
- Mizurou Tamaki - 5th Academy Junior
- Koori Ui - 1st Academy Junior
- Masami Umeno - 6th Academy Junior
- Kuki Urie - 7th Academy Junior (Honors Curriculum)
- Kurona Yasuhisa - 2nd Academy Junior
- Nashiro Yasuhisa - 2nd Academy Junior
- Saiko Yonebayashi - 7th Academy Junior
- Bonus discussion between Yukinori Shinohara and Juuzou Suzuya at the end of Volume 6.
- Tokyo Ghoul Chapter 17
- Tokyo Ghoul Chapter 102
- Tokyo Ghoul:re Chapter 24
- Tokyo Ghoul:re Chapter 37
- Hirako Squad profile in :re Volume 2.
- Tokyo Ghoul:re Chapter 13
- Tokyo Ghoul Chapter 95
- Tokyo Ghoul:re Chapter 5
- Suzuya Squad profile in :re Volume 3.
- Koutarou Amon's profile in Volume 6.
- S1 Squad and Fura Squad profile in :re Volume 4.
- Quinx Squad profile in :re Volume 1.