Griswald's Grammar School is a secondary school in Tackleford (located at Coward Cross Road, Keane End), covering the seven-year span between primary school and university (generally roughly ages 11 to 17). Successive waves of characters have been shown attending this school over the years, and Expecting To Fly was a "flashback" to the 1990s school days of some characters earlier seen only as adults. Early appearances of the school didn't always show a consistent name; it was sometimes "Tackleford Grammar School" or Griswell's.
According to its sign, Griswald's was founded in 1701, which would make it predate the city of Tackleford itself, which had its bicentennial celebration in 1960 indicating a 1760 founding. Esther was probably exaggerating a bit when she referred to the school's "troubled 500-year history" when giving anecdotes about her school days to a friend in college (Giant Days #34).
The school uniform has a white shirt and red tie, with dark grey trousers (for the boys) or skirts and stockings (for the girls). On top is a blue blazer with a yellow "G". In "The Case of the Forked Road", the uniform of 1960 was seen, which is similar to that of the present day, except that boys would wear shorts in the warmer times of year (school was in session as late as July) and there was also an accompanying beanie cap.
- "Tubby" Glossop, was a causality of the incident that created the time hole in 1960.
- George Bough (pronounced "boff")
- Mr. T. Knott, wears an eye patch due to an invention-related accident in 1996. Was the much-feared head of discipline until Blossom Cooper cursed him out, leading to his collapse and (temporary) retirement.
- Ward Bostwick, the new head of discipline, with a much more laid-back, new-agey approach than Knott. Died in office, aged 43.
- Bob Crowley was the headmaster in 2006-07 after being summoned by a ritual performed by faculty members.
- Mr. Daimler, one of the faculty members responsible for summoning Crowley.
- Mrs. Liversey, suggested the "Battle of the Bands" to Crowley.
- Derek Pevenser , who, back in 1973, already had the same idea as Mrs. Liversey.
- Mr. Cole, Pevenser's superior in 1973, so presumably the schools headmaster at this time.
- Old Flopsy, whose speeches were, er... very inspiring. Once announced Esther de Groot to be the new head girl.
- Mr. Wyrmwood-D'Eath, casted the deciding vote that made Esther the new head girl.
- Ryan Beckwith becomes a teacher in the 2010s. He also leads the student drama productions. After the OFSTED intervention, he becomes the school's deputy head.
- Abigail Lord , responsible for the swimming team  , and married to the much older Ken Lord.
- Derek Sprink  , the Latin teacher.
- Tony Bond , who seems to be attracted to Abigail Lord.
- Mr. Hurst, another faculty member attracted to Ms. Lord.
- Miss Perks, claims to have a boyfriend, but nobody believes her.
- Mr. Pardew, was teaching rugby in 1996, but at some point during the next ten years died of scrum pox and complications caused by an exploded cauliflower ear.
- Mrs. Lamb, who led the drama productions in the alternate timeline of "Case of the Forked Road", in which Mr. Beckwith wasn't on the faculty.
- Mr. Verlaine, the art teacher.
Staff / Assistants / Temps Edit
- Anthony Calvin Goater ("Grumpaw") works as a lab assistant. After the changes in history caused in "The Case of the Forked Road", a new timeline is in effect in which he took an early retirement and was not around the school contemporariously with the "Mystery Kids", as he was in the original timeline.
- Mr. Rabbit, a giant talking rabbit also known as Mr. Pooka  and Mr. Lapin , Headmaster Crowley's right hand man.
- Mr. Manuel, actually Headmaster Crowley's two Mooncalf  assistants, disguised as a human. Some students suspected that there is something "wrong" with him, but couldn't quite figure out what.
- Elodie Broussard has a temporary appearance as French assistante.
- Anthony Calvin Goater, later known as "Grumpaw", was a student in the early 1960s.
- Tommy Hurst, a classmate of Calvin. Responsible for creating a wormhole through time, by placing fireworks into a fume cupboard, shortly before an atomic energy demonstration was carried out in there.
- Shelley Winters was a student in the 1990s.
- Mandy Beasant, Shelley's best friend, who committed suicide in 1996
- Tim Jones
- Ryan Beckwith (who dropped out in 1996, falsely claiming to be expelled, after taking the blame for Tim's mishap causing inujry to Mr. Knott's eye)
- Riley Beckwith
- Eustace Boyce ("The Boy"), who attended school in the 2000s
- Erin Winters
- Esther de Groot
- Sarah Grote
- Big Lindsay
- Paul Milford, the best friend of Eustace
- Oggy, another friend of Eustace
- Roxy Postlethwaite (was a normal student until she got hypnotized by the father of The Child , which kicked off her music career )
- Pepe, the nephew of Hugo Rodriguez, saw Roxy performing at "The Battle of the Bands" in school, and recommended her  - thus he might be one of the students, but that is not certain.
- Edwin, the winner of the "Battle of the Bands" for his exceptionally sad performance 
- Carrot Scruggs, the son of Tackleford Cormorant editor Paula Scruggs
- Gary Parsons, a bully who wanted to beat up Carrot 
- Jessica Finch, Jack's big sister, with overlapping school times
- Lauren Field, Jessica's friend
- Sian, another friend of Jessica and Lauren 
- Silje, the fourth member of Jessica's friend group
- Charlotte Grote
- Shauna Wickle
- Mildred Haversham
- Sonny Craven
- Linton Baxter
- Jack Finch
- Tuan Hoang (gaming nerd; was removed or expelled from the school)
- Blossom Cooper (gaming nerd; some romantic involvement with Tuan; became Top Bitch Of the Year)
- Tania Lewis (former Top Bitch, defeated in a fight by Blossom Cooper)
- Louise, who wears her hair covering her eyes, and is prone to making smart-ass remarks. She was watching when Blossom beat up Tania, as well as a little later when Mr. Knott collapsed while teaching.
- Mosstyn Corkindale (Corky), a friend of Tuan and Blossom, who had a huge crush on Shauna.
- Claire Little ("Little Claire")
- Colm O'Shaunessy, who was Claire's boyfriend for several years.
- Nikki and Jasmine (briefly friends with Mildred: )
- Lem, a right good laugh, once you got to know him. Or so he claimed. Was actually an onion baby grown by two aliens  from planet Korfus.
- Oliver Spain, up to mischief and mayhem with his friends, twin brothers Marc and Adam (though one of them is referred to as Luke at one point)
- Keith (Shauna's boyfriend in an alternate timeline; doesn't exist in the "real" timeline)
- Ellen Selky, whose surname (with a spelling suggested by Mr. Bough) hints at the fact that she was actually a selkie. Was accidentally assumed to be a transfer student.
- Sasha Wembley, the all-county swimming champion, and also secretly a selkie.
- Lee Chaplin and his two mates. Lee found Sasha's selkie pelt when he was a young child.
Time/Space/Dimensional Portals Edit
A portal to Hell was opened up on the school grounds once, into which Erin Winters and Bob Crowley were pulled. Crowley had originally been brought into the school by a portal-opening ritual performed by some faculty members, and become the headmaster.
A time portal was opened in the laboratory by a student prank gone bad in 1960, resulting in an explosion and a portal opening to the future; this resulted in the school in the 2010s having a gateway from a lab cabinet to a "looping" single day of July 1960. It has since gone away once history was changed.