Rudd is in final negotiations to join the project from Sony that will be released into theaters on July 10, 2020.
The official Ghostbusters Twitter account confirmed Rudd's involvement on Thursday by uploading a video of the actor standing in front of the fire station that serves as the team's headquarters.
"When I heard they were gonna call me well, as you can imagine, I nearly slimed myself," Rudd says in the clip. "I can't wait to join the cast this fall for Ghostbusters.
Rudd is slated to portray a teacher in the film. Carrie Coon (The Leftovers), Finn Wolfhard (Stranger Things) and McKenna Grace (Captain Marvel) are also set to star.
"It's going to be crazy working with the guys again," she said.
Reitman, who is the son of director Ivan Reitman who helmed 1984's Ghostbusters and 1989's Ghostbusters II, is co-writing the new film with Gil Kenan (Monster House, Poltergeist). His father is producing.
Weaver, Murray, Aykroyd and Hudson had cameo roles in Sony's 2016 Ghostbusters film, which featured Kristin Wiig, Kate McKinnon, Leslie Jones, Melissa McCarthy and Chris Hemsworth. The 2016 film did not take place in the same timeline as the originals.