Officers were called to The Time Piece in Northgate just before 9.40am.
An elderly driver was aided at the scene but was not thought to be seriously hurt.
A West Yorkshire Police spokesman said: "“At 9.38am today police received a report of a vehicle which had crashed into The Time Piece pub in Northgate, Dewsbury.
“Emergency services attended and found a grey Saab estate car had gone into the building.
“The elderly driver of the car [was] receiving medical treatment at the scene, but is not thought to be seriously injured.
“No other injuries have been reported and the vehicle has now been removed.”
West Yorkshire Fire and Rescue Service said that crew members from Dewsbury and Cleckheaton attended.
"One adult male was trapped and extricated by Fire Service and left in care of Ambulance Service," a spokesman said.
"Two appliances from Dewsbury attended along with technical rescue vehicle from Cleckheaton."
Fire engines, ambulance and police vehicles"converged" in Dewsbury town centre, according to one witness who posted about the crash on Twitter.