The third draft screenplay of Back to the Future was written in July 1984 by Robert Zemeckis and Bob Gale. Three years separate this draft from the second draft.
- The town is now named Elmdale, and is located somewhere in the Midwest.
- Jennifer Parker is still Suzy.
- Marty wants a Camero Z-28, instead of the Toyota 4X4.
- Marty is no longer a video pirate.
- Doc Brown lives in a Victorian home, with his lab in the garage.
- Twin Pines Mall is Three Pines Mall.
- Marty travels to 1955, but on March 20.
- Marty wears red underwear, not purple.
- Lorraine only has one brother, not an entire family of siblings.
- Lorraine is to go to the dance with Biff and Marty as an alien scares Biff instead of George to force him to change his mind.
- The Enchantment Under the Sea dance is still known as Springtime in Paris.
- Marty plays the Bill Haley song "Rock Around the Clock", instead of "Johnny B. Goode".
- The time machine is driven 1435 miles in 15 hours to Nevada to intercept the atomic test.
- Lou notices that Marty's money is from 1978.
- When driving towards Nevada, Marty drives through Texas, Oklahoma, and Missouri. It's unclear what state Elmdale is located in.