The typeface used for the title of "The Great Gatsby" is a custom font designed specifically for use in the movie's promotional materials called Deco Pinstripe. Deco Pinstripe is the work of an Australian design firm, Like Minded Studio.
The font was designed to help emphasize the glitz and glamour of the Roaring 20s and to promote how stylish the movie was. Deco Pinstripe draws inspiration from other vintage art deco typefaces and consists of alternating solid and pinstriped letters. While Deco Pinstripe is not available for general use, the typefaces it was styled after are available in both commercial and free versions. The best known commercial versions of these are Atlas and Atlas Solid.