Firefighters were called to St Cuthberts and the First Martyrs Catholic Primary School on Fairfield Street at 2.40pm today (May 11).
An empty Year 6 class room was involved in the blaze.
Executive head teacher Daniel Copley said: “The school will be closed for the rest of the week so we can do assessments to see what is best for the children over the coming months.
“Nobody was injured and everyone was evacuated really quickly.
“Everyone is safe and investigations are ongoing into the cause of the fire.”
Seven fire engines attended the scene, which involved a single storey building that was 25 per cent involved in fire.
Crews from Fairweather Green, Odsal, Rawdon, Shipley, Bradford, Cleckheaton and Idle were in attendance.