Gracie Abrams L.A. Concert Draws Paul Mescal, Lucy Hale, Noah Beck & More

Gracie Abrams brought down the house Thursday night in Los Angeles ... with some of Hollywood's youngest stars eating it all up.

It all went down at the Kia Forum -- part of her "Secret of Us" tour -- where she poured her heart out to a hometown crowd ... with celebs like Paul Mescal, Lucy Hale, Noah Beck, Tyler Blackburn, Lola Tung in the audience.

Paul is seen near the front row with a big smile on his face, clapping and singing along as Gracie performs her hit "Free Now."

Lucy Hale and her former "Pretty Little Liars" costar Tyler Blackburn snapped a smiling selfie in the crowd together, posing in matching white tops.

Noah Beck is looking suave ... chopping it up with "The Summer I Turned Pretty" star Lola Tung while rocking a backwards hat, as the two enjoyed their balcony seats.

Gracie fans went wild when she played a 10-minute version of Taylor Swift's "All Too Well." As Swifties know, Gracie was one of the opening acts on Taylor's famed "Eras" tour.