The memorial will be held at the Hall of Liberty at Forest Lawn Cemetery Hollywood Hills at 1 p.m. PT. Fans can attend on a first-come, first-served basis, and when the hall fills up, they'll be able to stand outside and watch the service on screens.
Can't make it to California? The whole thing will be live-streamed on Reynolds' website.
Reynolds' son, Todd Fisher, told Variety not long ago that the memorial was what his mother would have wanted.
"She was very connected to her fans and felt they were a part of her," he said.
Todd Fisher also said that a video of a song that James Blunt wrote as a tribute to his sister will be released on the day of the memorial. Blunt and Carrie Fisher were good friends; before he found fame with his hit "You're Beautiful," he actually lived with her.
"It might rip your heart out," Fisher said of the song.