Deadline reported Thursday that Amazon acquired the U.S. and Latin American rights to the film from A24, which controls the remaining global rights.
Val is directed by Leo Scott and Ting Poo. The film features interviews with Kilmer and hours of footage supplied by Kilmer from throughout his life and career.
"At least once a day for years I looked around and got this bittersweet feeling that there are a thousand reasons that this project could've been shipwrecked," Kilmer said in a statement. "I mean, what could a film look like of a man filming himself, sometimes daily, years at a time?"
"It is unimaginable that this movie actually could've ever come to light without the partnership of my dear friends, Leo and Ting, and my producing partners," he added.
The Hollywood Reporter said there are reports that Val will make its world premiere at the Cannes Film Festival this year. The festival will announce its lineup next week.
Kilmer is known for such films as Top Gun, The Doors and Batman Forever. He will reprise Tom "Iceman" Kazansky in the Top Gun sequel Top Gun: Maverick, which opens in theaters in November.