Henry Grayle best known as Mr. Grayle is a minor character in Carrie. He is the principal of Ewen High School in Chamberlain, Maine and works alongside Miss Desjardin and Mr. Morton.
He supports Miss Desjardin´s and Mr. Morton´s idea into punishing the girls for bullying Carrie White. He also takes a successful stand against John Hargensen, when he tries to threaten him into reinstating his daughter Chris by showing his legal expertise to him. He is also worried about the upcoming Prom because of Chris's plans.
He happily later survives The Black Prom, but is shocked to the core because of the events and later resigns due to the guilt of not being able to get through to Carrie, for not having stopped the bullying in time, implying he knew about what was going on, but acted only too little regarding it and too late and for not having protected the Prom as he should have despite of the fact that he knew something could happen at it.