The ambulance had been responding to an emergency call with blue lights and sirens in operation when the incident happened on the A803 Glasgow Road near the Mariner Leisure Centre.
Police in Falkirk responded at around 3.50pm and the road was closed for a time.
The injured man was taken to Forth Valley Royal Infirmary, reportedly by a second ambulance.
His injuries are not life threatening.
Enquiries are continuing, and anyone who witnessed the collision is asked to contact 101 quoting incident number 2727 of 8th June 2019.