Principal Tom Petersen, usually known as Principal Petersen is the principal of Medford High School.
Like many of the teachers and the students, he wants Sheldon out of this school. However, he also realizes that Sheldon has the highest aptitude test score, and that gives funding for the school.
In the episode "Graduation," he reveals that he was the son of a teenage mother to a distraught female student who discovers that she is pregnant.
- An Eagle Feather, a String Bean, and an Eskimo
- A Sneeze, Detention, and Sissy Spacek
- Killer Asteroids, Oklahoma, and a Frizzy Hair Machine
- A Loaf of Bread and a Grand Old Flag
- Albert Einstein and the Story of Another Mary
- A Perfect Score and a Bunsen Burner Marshmallow
- A Political Campaign and a Candy Land Cheater
- The Sin of Greed and a Chimichanga from Chi-Chi's
- Teenager Soup and a Little Ball of Fib
- A House for Sale and Serious Woman Stuff
- A Secret Letter and a Lowly Disc of Processed Meat
- An Existential Crisis and a Bear That Makes Bubbles
- A Virus, Heartbreak and a World of Possibilities