Castleford Park Junior Academy caught fire today (Tuesday).
Four crews were called to Leake Street to tackle the blaze at around noon.
It has now been put out.
A West Yorkshire Fire and Rescue spokeswoman said: “It was a fire involving the roof of a single story extension.
“Four fire engines attended from Castleford, Wakefield, Normanton and Garforth.
“Nobody was hurt. The school was closed for the holidays.”
Black smoke could be seen billowing from the school in a video posted online by eyewitness Mark Vause.
Crews are now dampening down at the scene.
An investigation into the cause of the blaze is being carried out.