- This article is about the grade. For information on the Season 4 episode, see "Fourth Grade".
The 4th grade is the class that most of the South Park Elementary students are in since the episode "Fourth Grade". Mr. Garrison's class encompasses most of the students, although there is likely another fourth grade class because many students do not appear in his class.
- Herbert Garrison - 3rd grade teacher from "Cartman Gets an Anal Probe" to "Cartman Joins NAMBLA". Returned to the school as a kindergarten teacher in "Trapper Keeper". He was rehired as a 4th grade teacher in "The Death Camp of Tolerance" and was fired from the entire school in "Where My Country Gone?" for calling his Canadian students "Canucks" and interrupting the Canadian history assembly only so he could insult the Canadians.
- Ms. Choksondik - The main Fourth Grade Teacher from "Fourth Grade" to "Professor Chaos".
- Mr. Mackey - Covered after Ms. Choksondik's death, also teaching computer class and drug lessons.
- Mrs. Nelson- Mr. Garrison's replacement after he was fired for interrupting the Canadian history assembly. So far she has only appeared once teaching the class about planets breifly during the Whole Foods Inspection.
- Mr. Slave - Mr. Garrison's teaching assistant From "The Death Camp of Tolerance" to "Fat Butt and Pancake Head " and "South Park is Gay!". He was part of Mr Garrisons get rich quick plan, which backfired and ended with a forced stay at the Tolerance Camp for a week.
- Mrs. Dreibel - Teaches art in her own classroom during "Toilet Paper"
- Richard Dawkins - Teaches evolutionary studies.
- Mr. Adler - He is the teacher in Shop Class.
- Pearl - She teaches home economics.
- Main article: List of 4th graders
Students in this section are seen in Mr. Garrison's fourth grade classroom in almost all episodes.
- Annie Faulk
- Bebe Stevens
- Butters Stotch
- Clyde Donovan
- Craig Tucker
- Eric Cartman
- Jimmy Valmer ("D-Yikes!" onward)
- Kenny McCormick
- Kyle Broflovski
- Stan Marsh
- Timmy Burch
- Token Black
- Wendy Testaburger
Students that are occasionally seen in Mr. Garrison's class.
- Boy with Red Shirt and Blue Pants
- Bradley Biggle
- Heidi Turner
- Kevin Stoley
- Peter Mullen
- Sally Turner
- Tweek Tweak (regular until "Elementary School Musical")
Students who formerly appeared, but have either inexplicably vanished, moved away, or died.