Los Angeles, California - Olivia Rodrigo shared a sweet message of gratitude after receiving an outpouring of love on her 21st birthday.

The newly-21-year-old star showed off her GUTS-themed birthday cake in a new Instagram post on Tuesday, which kicked off with a photo of herself smiling beside the cake.

"21!!! so grateful for all of the incredible things I've been able to experience so far and so excited for all the good times ahead," she wrote. "thx 4 all the love."

The post also included a clip of her under a flood of balloons as she was serenaded, with the slideshow wrapping up with an adorable throwback snap of baby Liv.

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Over on TikTok, the Grammy winner shared a longer video from the celebration, setting it to a snippet of the song teenage dream from her sophomore album.

The latest celebrations, which came days after her proper birthday bash over the weekend, appear to have been held amid her preparations for the GUTS World Tour.

Olivia is set to kick off the first arena tour of her career on Friday, with the first stop in Palm Springs, California.

The preparations led her to shift her birthday plans forward, hosting a star-studded party on Saturday before returning to rehearsals on the big day.

The 75-show concert series is currently set to wrap up in August, with stops running through North America and Europe.

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Olivia will be supported by opening acts Chappell Roan, The Breeders, Pinkpantheress, and Remi Wolf on select dates.

If you're lucky enough to be heading to a show, be sure to check out TAG24's picks for the best accessories to rock at the GUTS World Tour.