Jenna Bush Hager Announces Scarlett Johansson as “Today” Guest Co-Host After Hoda Kotb's Departure (Exclusive)

"The fact that she's coming to give us a week of her time — she could be doing anything — is a testament to the show that we have built," Bush Hager exclusively tells PEOPLE

Scarlett Johansson has a new gig!

The Black Widow star will be joining Jenna Bush Hager on Today with Jenna & Friends as a guest co-host, beginning Monday, Jan. 20, Bush Hager tells PEOPLE.

"Scarlett Johansson is the queen! First of all, I've been obsessed with her movies since forever. The Girl with a Pearl Earring, I mean that shows you I'm a nerd who loves to read," theToday star, 43, says. "She's also a big reader, which will be so much fun. We have so much in common."

Both Bush Hager and Johansson have twin siblings, and they also have daughters similar in age. Johansson's daughter Rose is 10 years old, while Bush Hager's eldest, Mila, is 11.

"It's just a wild dream. But that's what I'm saying, the fact that she's coming to give us a week of her time, she could be doing anything, is a testament to the show that we have built. So I am beyond thrilled. I cannot wait," Bush Hager adds. "We've never seen Scarlett Johansson host a daytime show before!"

Today with Jenna & Friends will launch Jan. 13, following Hoda Kotb's last day on Jan. 10. Bush Hager announced on the Jan. 6 broadcast that a rotating list of celebrity guests would be stepping in to help fill the empty slot before Johansson takes over. The stars include Taraji P. Henson, Eva Longoria and Keke Palmer.

"What's so cool about it is that it really does feel like we're pulling up chairs for all different types of people," says Bush Hager. "Yes, we have actors, but we also have comedians and people in media. And I think that really is what we're hoping to have: a total representation of who watches our show and something for every viewer."

Related: Jenna Bush Hager and Hoda Kotb Cry on Air amid 'Depression Stage' Ahead of Kotb’s Today Show Exit

Still, with all of the excitement that comes with kickstarting a new "era" for the fourth hour of Today, Bush Hager would be remiss if she didn't admit that everything feels particularly "bittersweet," too.

"I adore Hoda. She's the best partner. She's been the most generous partner, and we are truly really great friends, so the thought of her not being here is almost too much to bear," Bush Hager says.

Related: Hoda Kotb Has Emotional Moment with Savannah Guthrie at Final Rockefeller Christmas Tree Lighting Before Her Today Exit

In the week leading up to Kotb's departure, Today is putting on a "Hoda-bration" in her honor, culminating in one final, live show on Jan. 10 in Rockefeller Center's Studio 8G. On the Jan. 6 episode, Kotb was surprised by 70 of her former Tri Delta sorority sisters from Virginia Tech.

"Obviously, I've had months to wrap my head around it, although I cannot promise that our last Hoda-bration won't also be filled with tears. I'm sure it will be just because I can't help it," says Bush Hager. "I'm excited and nervous and thrilled, and I'm also really, really going to miss Hoda."

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Today airs weekdays, beginning at 7 a.m. ET, on NBC.