Various schools other than Super Hero High School are mentioned in DC Super Hero Girls. There are originally fifty teams at the 100th Super Triathlon, meaning there are likely at least fifty schools.
Lois Lane tells Wonder Woman that she often goes to CAD Academy to write profiles of up-and-coming super heroes, saying that it's located in "the next town over". CAD stands for Carmine Anderson Dayschool, but many think it stands for Criminals and Delinquents. Many of its faculty members are supposedly reformed supervillains, and many suspect it's a launchpad for supervillains rather than a school for superheroes. During the 100th Super Triathlon, they do well during the interview portion and make it to the finals, winning the first round and getting second place. Their unofficial motto is "Live Evil". Attendees of the school include Captain Cold, Ratcatcher, Heat Wave, Magpie, and Golden Glider.
Cavalier Community School
Cavalier Community School makes it to the semifinals of the 100th Super Triathlon. A group of unruly parents from this school have to be forcibly removed when the school doesn't make it to the finals.
Foundation for the Telepathic and Telekinetic Talented & Gifted
Foundation for the Telepathic and Telekinetic Talented & Gifted makes it to the semifinals of the 100th Super Triathlon.
Gotham City High
Intensity Institute was the three-time champion of the Super Triathlon, and make it to the semifinals of the 100th Super Triathlon.
Wonder Woman describes Interstellar Magnet as "snooty" and very selective. They had the "inside track" for the academic portion of the Super Triathlon, and later win the academic portion. They make it to the finals of the 100th Super Triathlon, winning the second round and getting third place. Kanjar Ro was their team captain, with the superhero Maxima also on the team.
CAD Academy's team mocks Pluto Prep's mascot before the 100th Super Triathlon.
Powers Alternative Education
Powers Alternative Education makes it to the semifinals of the 100th Super Triathlon.
Skartaris High School
Unnamed Bismol School
A "controversial ad hoc team" of homeschooled super heroes from a small suburb on the plant Bismol make it to the semifinals of the 100th Super Triathlon. They are only known by a symbol of an eye-like shape with five eyelashes above the eye and a swirl in place of an iris and pupil.
Wheeler-Nicholson Prep makes it to the semifinals of the 100th Super Triathlon. When they don't make it to the finals, their team throws down their weapons and stomp on them in protest.