According to entertainment portal Pagesix.com, Depp has hired a Beverly Hills event planner to orchestrate the event that will take place behind Thompson's Colorado compound Aug 20.
Thompson, who had been in failing health, shot himself at his home Feb 20.
Depp had played the author in the movie "Fear and Loathing in Las Vegas", which was based on Thompson's book about his experiences in the city.
Depp got close to Thompson when he lived with him at his house while researching his role for the film.