The principal of Baldwin Middle-Senior High School has been removed from her position after "a series of incidents at the school," a Duval County Public Schools spokeswoman said.
Rhonda Motley was removed this week and placed on temporary assignment.
Spokeswoman Marsha Oliver said Superintendent Nikolai Vitti became concerned about the culture at the school and felt a leadership change was needed.
Denise Hall is the new principal. She came from Lee High School.
The move comes after two fights were captured on cellphone video in a matter of days.
Kyle Stewart, 17, said he was blindsided by one of his classmates. He's seen in cellphone video getting punched repeatedly while simply sitting at his desk in science class.
Another video shows what appears to be another student holding a cellphone and egging on a teenage girl to hit another teenage boy. The scene quickly escalates and turns violent as the teenaged girl starts hitting the boy in the video.
A swarm of students in the cafeteria erupt from their chairs as the chaos unfolds.