Permanent Detention is a detention center in Gallagher Elementary School. It houses students that are caught breaking rules.
In Operation: E.L.E.C.T.I.O.N.S. Nigel was briefly sent there and locked up. He used a G.U.M.M.B.O. and uses this to break out of detention. He also helped break out Wilson Woodrow when he was locked up as well.
In Operation: M.E.S.S.A.G.E. it's revealed, that Ex-President Jimmy is locked up at Kids Next Door Arctic Base for what he did in Operation: S.N.O.W.I.N.G., still attends Gallagher Elementary School, but is serving time in Permanent Detention.
In Operation: C.R.I.M.E. many students were sent to permanent detention after Crayon Boy pretended to have psychic future drawing abilities, causing them to be sent there.
In Operation: P.R.E.-C.R.I.M.E. Muffy Jenkin's arrest was ordered by Joe Balooka when Crayon Boy "predicted" that she would be chewing gum during class next Tuesday. By the end of the day, Crayon Boy had every single Gallagher Elementary student placed in permanent detention, even the Hall Squad.
- Nigel Uno (temporarily): for plotting against the Delightful Children.
- Muffy Jenkins (temporarily)
- Jimmy Nixon McGarfield
- Anna Worthington
- Wilson Woodrow (temporarily)
- Wally Beetles: for the wedgification of Pauley Marcus
- Hoagie Gilligan: for assaulting an officer and interfering in hall monitor business.
- Joe Balooka: for cheating on tomorrow's pop quiz
- The Delightful Children From Down the Lane: for running in the halls
- Scotty Vincent: for having water balloons.
- Kuki Sanban (but not taken away): for pulling the fire alarm tomorrow.
- Various students: for starting a food fight, shooting spit balls at next weeks substitute gym teacher, chewing gum in class.
- It is set up like a jail cell with kids in separate cells.
- Ernest's bully friends once served permanent detention. They were hired by the Delightful Children to guard the cells, alongside the Six-Gum Gang.
- Rulers would be used to paddle troublemakers.
- The B.O.N.G.O.S.K.O.P.E. was invented to be used to rescue KND operatives from permanent detention.