The film, screened out of competition, will be shown on May 15th, coinciding with its launch across France.
Cannes, widely rated as the world's top film festival, climaxes on May 26th with awards selected by a jury headed this year by Hollywood legend Steven Spielberg.
Set on the US East Coast of the Roaring Twenties, Gatsby stars di Caprio as Fitzgerald's mysterious millionaire, battling to win the heart of a girl he courted in his youth.
The film was scripted by Australian director Baz Luhrman and his long-time co-screenwriter Craig Pearce. It will be shown in 3D, for the second time in the festival's history, after the animated picture Up in 2009.
Luhrmann, 50, is a familiar figure at Cannes, where he has been twice honoured, for Strictly Ballroom in 1992 and Moulin Rouge! in 2001. He said he was thrilled to return to the Riviera city.
"F. Scott Fitzgerald wrote some of the most poignant and beautiful passages of his extraordinary novel just a short distance away, at a villa outside St. Raphael," he said in a statement.