A Year 4 pupil at Villiers Primary School has a confirmed case of coronavirus, and all other pupils and staff in the year group have been sent home.
The school is the latest of dozens of schools in the region to be affected by Covid-19 cases since students returned in full for the first time since March.
Some schools have only sent home people who have been in direct contact with students or staff who have tested positive, while others have told entire year groups to self-isolate.
Lisa Westwood, headteacher at Villiers, said: "The child contracted it outside of the school. Naturally we contacted Public Health and followed guidance.
"As a precaution we've sent all staff and the Year 4 bubble home, all their families have been really supportive.
"We've got good measures in place to keep the students and staff safe.
"Their teachers will continue to teach them from home.
"They will be back in school on October 2.
"I just wanted to thank all our parents for being supportive of the action we've had to take."