The first name of Selena Gomez's character is Grace and the last name of Leighton Meester's character is Kelly. Grace Kelly was an American actress who became Princess consort of Monaco. Monte Carlo is located in Monaco.
The production spent four days filming in Paris and two weeks filming in Monaco. The rest of the filming took place in Hungary with Budapest doubling for Paris and Monte Carlo. Raleigh Studios Budapest was used to substitute for Monte Carlo's Hotel de Paris for the filming.