ROLE MODEL Brings Out Hilary Duff At Austin City Limits

ROLE MODEL might have brought out one of his most iconic 'Sally' guests yet during his Austin City Limits performance ... and it's none other than the Disney queen herself -- Hilary Duff!!!

In case you aren't aware of ROLE MODEL's viral, fan-favorite bit he does when performing his hit song "Sally, When the Wine Runs Out" ... it began with the indie-pop star bringing up fans from the crowd to join him on stage and dance around to be his "Sally" for the night -- but then grew into celebrities like Kate Hudson, Natalie Portman, & Olivia Rodrigo making guest appearances.

ACL is basically Austin’s Coachella -- minus the desert, but plus BBQ goodness -- the city's biggest green space turns into a two-weekend music haven with massive headliners that takes over Zilker Park every October.

This year, the lineup is stacked with stars like Sabrina Carpenter, Hozier, Luke Combs, The Strokes, John Summit, Doechii, and originally Doja Cat -- however, Doja later pulled out, and The Killers have stepped in as her replacement for the Sunday slot.

This surprise appearance comes just weeks after HD hinted at potential "new music" in the works ... teasing the docuseries that is tied to her new album, which will be directed by and executive produced by Sam Wrench ... who brought Sabrina Carpenter's Christmas special and Taylor Swift's "Eras" tour concert film to life.

Fans are hopeful that this Sally surprise might lead to a music collab for the two singers ... but for now, the Lizzie McGuire stans are just going to have to keep on dreamin'.