A number of pupils and staff at The Wensleydale School are having to isolate following a confirmed Covid-19 case.
The school said the positive test was within their Year 10 bubble.
Following instruction from Public Health England, all Year 10 students have been sent home to self-isolate for 14 days.
Headteacher Julia Polley confirmed the positive test in a letter to all parents.
She said: “We have been made aware that a member of our school community has tested positive for COVID 19.
“We know that you may find this concerning but we are continuing to monitor the situation and are working closely with Public Health England.
“This letter is to inform you of the current situation and provide advice on how to support your child. Please be reassured that for most people, coronavirus (COVID-19) will be a mild illness.”
The head said the students and staff who have been in close contact with the individual who had tested positive had received a letter informing them that their child must stay at home for 14 days and must not return to school until Thursday, November 5.
“The school remains open and your child should continue to attend as normal if they remain,” Mrs Polley added.