In a letter to parents, Royal Wootton Bassett Academy headteacher George Croxford says the school will be closed today.
On the school's website he says: "We have been informed by the NUT union that they will be taking industrial action in the form of a strike on Wednesday 26th March 2014.
"This action is not against the academy itself but is part of national industrial action organised by this trade union concerning teachers’ pay and working conditions and changes to the pension schemes of their members.
"There is no requirement on the union to inform us of which members of staff will take action. However, we have been given an indicative number of staff who will not be at work on that day by the respective union representative.
"Having reviewed the timetable requirements for the day, in the light of the number of staff who will be absent, the decision has been taken to close the School to students on this day.
"Neither the governing body nor the headteacher is legally allowed to close the school ‘in sympathy’ with the strike and we are not doing so.
"Our main concern is the safety of our students and it is clear, given the numbers of staff who will not be at work that day, that there will be insufficient staff to supervise the students in an effective manner should the school remain open. Work will be set for students, to minimise the impact on their education.
"We must all hope that the issues over which the Industrial Action has arisen are resolved as soon as possible."