Two adults, 23-year-old Dante Smith and Natanya Johnson, 33, were arrested after the incident. Smith and Johnson were both attendees at the graduation ceremony.
The video appears to show two women fighting before a group of men enter the picture and get involved in the fray.
"Why would they fight at a graduation when you're supposed to be celebrating that you got out of high school?" student Kennedy Myers said to WJZ. "I kind of hope we don't have our graduation in our auditorium."
No one was hospitalized after the fight.
"The altercation that happened outside the graduation ceremony yesterday was an unfortunate distraction from the graduates and their family members who came to honor and support their accomplishments," Baltimore County Public Schools said in a statement.
"We will continue to work with Baltimore County Police as they investigate the incident. In addition, there are still a few weeks left in the school year, and if we determine any current students were involved in yesterday's incident, they will face appropriate school disciplinary action."