Over a year since the Little Mix member's acclaimed debut single "Angel of My Dreams" was released, her debut album That's Showbiz, Baby! finally came out on Friday, Sept. 12 to positive reviews and top-3 chart success in her native United Kingdom.
"I've waited a long time for this moment," Thirlwall, 32, tells PEOPLE at the That's Showbiz, Baby! album release party (presented by Luis Fernando and Paul Tomasiello, a.k.a. P_A_T) on Sunday, Sept. 21 at 3 Dollar Bill in Brooklyn, New York City. "I'm really buzzing about it, and the response has been incredible."
Several singles were dropped in the lead-up to the full album's release, and Thirlwall was especially excited for fans to hear two in particular: "Unconditional" and "Before You Break My Heart," which interpolates a childhood recording of her singing the Supremes' "Stop! In the Name of Love."
It wasn't cheap to get approval to use the Supremes' 1965 classic, as Thirlwall admits she gave up "a lot" of her song's publishing royalties in order to do so. "I love Diana Ross and the Supremes, so it felt right to have a a song on the album that sampled that," she says. "So, whatever they take is fine by me."
Thirlwall also wrote directly with some other notable women in pop music for the album, including Tove Lo on "Lip Service." She explains of the track, "I like that it sounds innocent, but the lyrics are pretty filthy."
"We got on really, really well," adds the star of working with Tove Lo. "I think her last record [Dirt Femme] and particularly 'No One Dies from Love,' is one of the best pop songs ever written."
Additionally, Thirlwall worked with RAYE on the songs "FUFN," "Midnight Cowboy" and "Silent Disco," which she described as a "great" experience. "She's a one-of-a-kind talent," she notes of the "Escapism" artist.
"I've known her for years, so I think we have a mutual understanding of what it's like being a part of this music industry for a long time, especially as women and all the ups and downs that come with that," she says. "We had a good little bonding session over that, and she just gets it."
That's Showbiz, Baby! arrived just one week before Thirlwall's Little Mix bandmate Perrie Edwards released her debut solo album, and the group's third member, Leigh-Anne Pinnock, is launching a new era herself.
How do they feel about Thirlwall's album? "They messaged me congratulating me," she says. "I actually saw Leigh-Anne last night at an event, so we've seen each other. They've been very, very lovely."
Thirlwall will head out on That's Showbiz, Baby! The Tour to support the album with North American dates set for February 2026. Tickets are on sale now.