The video, which surfaced Wednesday, shows the teacher and the student arguing at Frederick Douglass High School on Gwynns Falls Parkway in Baltimore.
The student was not suspended by the school, according to the person who posted the video online. The person also said that the teacher had just returned to work after recovering from surgery related to cancer.
Classmates can be seen holding the student back before the girl swings at the teacher, connecting with the side of her face.
The teacher says that the girl isn't from the area. "F**k is you talking about," the student replies before punching her in the face. "Don't you f**king interrupt me, straight up," the student says before leaving the room.
The teacher then follows the student outside before the video cuts off.
The school is investigating what happened. In a statement, Baltimore City Public Schools condemned the student for striking her teacher, vowing to "continue to investigate a physical altercation that took place today when a teacher was struck by a student following a verbal exchange."