The actress also confirms that everyone from season one will be back!
Get excited, Big Little Lies fans.
"Y'all we're starting next Friday on Big Little Lies 2, I can't believe it," Witherspoon, who portrays Madeline Martha Mackenzie on the series, excitedly confirmed during her guest appearance on Late Night With Seth Meyers on Thursday. "Not only do we have every cast member coming back, but also Meryl Streep is joining us."
"[Meryl] sent an email to Nicole and I, and it said, 'OK, I read the part and I love it and I'm going to do it,'" Witherspoon recalled. "I, like, dropped the phone and then I called Nicole and was like, 'Is this real life?'"
Though we don't know too much about Streep's character just yet, we do know that she'll be playing Mary Louise Wright, the mother of the recently deceased Perry Wright (Alexander Skarsgård), the former husband of Kidman's character, Celeste Wright. She's described by HBO as a woman who arrives in Monterey searching for "answers" and "concerned" for the well-being of her grandchildren following her son's death.
Of course, Witherspoon isn't the only one who was ecstatic to learn of Streep's casting. Kidman and Dern could barely keep their cool when chatting with ET about their new cast member last month at the Calvin Klein runway show at New York Fashion Week.
"It's amazing!" Dern exclaimed. "When I tell anyone in my life that Meryl Streep is joining us, it's incredible!"
"Reese and I were just [thinking], 'She would be so amazing in the role!'" added Kidman. "We didn't think we'd get her. [The character] was written for her and we wanted her. It really is her standing up and going, 'I support you as women, and I believe in you.' I think that's a big statement from her. We're determined to give her an extraordinary experience. She's had a lot of experiences so we just want to make it fun for her and vibrant and exciting."
Big Little Lies is expected to return sometime in 2019. As we patiently wait for that to happen, watch the video below to hear more on the highly-anticipated second season!
Laura Dern and Nicole Kidman Gush Over Meryl Streep Joining 'Big Little Lies' Season 2 (Exclusive)