The show will be held Monday at a historic market not far from the headquarters of the French Riviera movie showcase, which is in full swing though May 22.
Campbell told Associated Press Television News that the theme of the show is red carpet, so "we thought it was appropriate" to stage it in Cannes.
She added, "You have to remind people that they still need help, so it had to be now."
Campbell's Fashion for Relief charity staged its first show in 2005 and says that since then it has raised 4.5 million pounds ($7.2 million).