The 21-year-old pop star has teamed up with the toy brand to create a fashion collection which features bright pink velour hoodies and wide-legged trousers emblazoned with the name 'Billie' in Barbie's instantly-recognisable Dollie Script font to celebrate the upcoming release of Margot Robbie's new movie based on the iconic doll.
The collection is available on Eilish’s own online merchandise story and also features vest tops, T-shirts, hats, necklaces and stickers.
As well as launching her own Barbie clothing collection, Eilish also contributed a song called 'What Was I Made For' to the movie's soundtrack.
In a post on Instagram, Eilish revealed she was shown some scenes from the movie early this year and threw herself into writing the track with her brother Finneas.
She explained: "In January, [director] Greta [Gerwig] showed me and Finneas a handful of some unfinished scenes from the film … We had noooo idea what to expect at ALL … We were so deeply moved. That next day, we were writing and COULDN’T shut up about it lolll anddddddddd ended up writing almost the entire song that night. To be real with you this all seemed to happen in a time when I really needed it. I’m so so thankful for that."
She added of the song's video: "This video makes me cryyyyy … It means so much to me and I hope it will mean just as much to you. Don’t have to say other than that, I think it will speak for itself."