Bourgoin players celebrate their semi-final win over Worcester
The European Challenge Cup final on Friday, 22 May has been moved from Gloucester's Kingsholm ground to the Twickenham Stoop.
French side Bourgoin said it would be hard for their fans to travel to the game with Northampton as the day before the match is a French public holiday.
The plea was initially rejected before organisers changed their minds.
"It was agreed across the board that a switch to London would benefit Bourgoin fans," said a statement.
The process of finding a suitable venue for the match began in January, with only English venues putting themselves forward.
Last weekend the semi-finals took place, with Bourgoin beating Worcester and Northampton seeing off Saracens. Afterwards, Kingsholm was announced as the venue.
"We have been open to the arguments put forward by Bourgoin who are delighted to reach this European final," said the statement from tournament organisers European Rugby Cup.
"To their credit Northampton Saints were very understanding and agreed to a switch as a gesture to the French club.
"ERC would like to acknowledge the magnanimous gesture by Northampton and the understanding and support of Gloucester Rugby with whom we have been preparing to stage the final."