Police were called at 2.23pm to a report of a serious crash in Main Street Garforth.
A Yorkshire Air Ambulance also landed in the street during the incident.
The woman tragically died at the scene due to her injuries.
A spokesman for West Yorkshire Police said: "Police are were called at 2.23pm to a report of a serious road traffic collision on Main Street, Garforth.
"A 71-year-old woman was seriously injured in the incident and despite medical attention, died at the scene.
"The 34-year-old male driver of a flatbed truck involved in the collision has been arrested in connection with the incident and is in police custody.
Enquiries remain ongoing this evening by the Major Collision and Enquiry Team.