Some 15 fire crews and three aerial appliances from across West Yorkshire were called to the fire after they were alerted to the incident at around 2.10am today.
A security company reported that a fire alarm was going off at Halifax bank in Southgate and when firefighters arrived at the scene to investigate they discovered smoke rising from the roof of nearby Poundland.
Within minutes of locating the fire the response was scaled up and extra fire crews were scrambled to the scene as the fire spread.
The seat of the fire was found to be on the third and fourth floors of a building in Southgate occupied by Game.
Firefighters estimated that approximately 40 per cent of the building was engulfed in flames and there was a risk that the fire could take hold of neighbouring buildings.
Six large jets were used to bring the fire under control, with various specialist officers also attending the incident.
There were no reports of anyone being injured.
By 6.30am, West Yorkshire Fire Service reported that the incident was now being scaled down, though the investigation into how the fire started is ongoing.
Calderdale Council issued advice to people travelling through the town centre this morning, tweeting: “Please avoid Southgate in Halifax. Fire this morning is extinguished, but structural damage being assessed.”