"The health and safety of our students and staff is the highest priority of the Freeport public school," principal Joseph Mille said.
The school said it is the first district on Long Island to offer vaccines to students. The on-site vaccination was in partnership with Northwell Health.
The students got the Pfizer vaccine, which earlier this week was granted emergency use authorization for children ages 12 through 15.
"I'm great, I'm ready for the second one," Kaylieann Jeanlubin, 12, of Freeport, told FOX 5 NY.
"Now they can go back to school, they can be around a large group of people without worrying about if they are going to get the virus or not," Keisha Jeanlubin, Kaylieann's mother, said. "It's very important for them to get."
All 300 appointments available were taken. Students who are 17 or younger had to come with a parent or guardian.
The Freeport School District said it is already talking to partners about hosting another event soon.
Get breaking news alerts in the FOX 5 NY News app. Download for FREE!