In a ceremony organised by railway police at Chiang Mai Train Station yesterday, the 19-year-old tourist, Ms Dhu Xiao, was presented with the cash by the 54-year-old driver, Boonthawee Somdetch.
The money was left behind on Friday.
Xiao had arrived in Chiang Mai on a train and hired the songtao at the train station to take her to a hotel.
When she realised she had lost the bag, she asked railway police to locate the driver.
Boonthawee later contacted police to inform them he had the bag.