Pham Thi Ngoc also had her driving license revoked for two months.
On July 1 she had driven Dabrowska Malgorzata from Apricot Hotel in Hoan Kiem District where the latter was staying to Times City urban area in Hai Ba Trung District.
The normal fare for the six-kilometer trip is around VND80,000, but Ngoc asked the Polish woman for VND400,000.
Dabrowska reported the incident to her hotel manager, who complained to local authorities.
Transport inspectors tracked down the driver. At a meeting with them on Monday Ngoc admitted to cheating the passenger and returned the excess money.
Gouging tourists has been a problem for a while now, affecting Vietnam's reputation as a safe and friendly tourism destination.