Los Angeles, California - Olivia Rodrigo left a few of her youngest fans in tears as she surprised trick-or-treaters on Jimmy Kimmel Live!

On Thursday, Olivia played a delightful trick on her fans in a viral segment for the late-night talk show.

The 21-year-old pop star was joined by comedian Guillermo Rodriguez, who first answered the door in an Olivia Rodrigo costume.

As he began to hand out candy to the trick-or-treaters, Olivia popped out to greet them as well.

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While several fans immediately recognized her, others couldn't quite believe it – with one even checking her driver's license to be sure!

One lucky Livie, who could barely pick up her jaw from the floor, even played along as Olivia challenged her to name as many of her songs as she could.

Sure enough, the young fan – who was dressed as a Hogwarts student – could name just about every Olivia song, including several deep cuts that led the Grammy winner to award her the entire bowl of candy.

Also on Thursday, Olivia gave fans a peek at her own Halloween festivities with a viral post revealing her costume, which was inspired by Elphaba from Wicked!