A Norovirus outbreak had closed Middlewich High School for two days.
The school says the sickness bug has significantly affected students and staff.
It will be closed Friday 29th November and Monday 2nd December.
In a statement the schools said: "We have taken advice from Public Health England and we are also supported in our decision to close by the Local Authority.
"Please be advised students must not return to school until 48 hours after final symptoms have ended.
"There will be no staff on-site to take calls during Friday and Monday as the site is being cleaned.
"Yr11 progress evening on Tuesday 3rd December will run as normal."