"First Day of High School" is the seventy-fifth episode of The Suite Life of Zack & Cody.
It is the first day of high school for Zack and Cody. Zack finds a new crush, Amber, (Kay Panabaker). Cody saves Bob from Vance, the school bully, Nia gets in trouble for defending Zack, and Mark (from Zack's summer school class in "Summer of Our Discontent") gets Cody's help to learn to be a geek and Cody and Vance get in trouble for fighting in the classroom and the two end up in detention along with Zack, Nia and Mark after Ms. Millitich, the school principal discovers the incident. London attends public school for the first time (after being expelled again from Our Lady of Perpetual Sorrow), in which she is out to tear down lockers for her own personal lounge.
- Kay Panabaker as Amber, Blythe Auffarth as Ellen, Kathy Najimy as Ms. Millitich, Giovonnie Samuels as Nia, Matt Angel as Vance
- Ashley Tisdale as Maddie Fitzpatrick