Hilary Duff starred as the pre-teen title character and also voiced McGuire's animated alter ego.
Duff will reprise her role in the rebooted series, and the show will follow her life as an adult on the brink of her 30th birthday.
"Lizzie has also grown up, she's older, she's wiser, she has a much bigger shoe budget," Duff said at the D23 unveiling. "She has her dream job, the perfect life right now working as an apprentice to a fancy New York City decorator, the perfect man who owns a fancy restaurant. She's getting ready to celebrate her 30th birthday."
Animated Lizzie will also return, and she will still be donning her classic pink tank top and jeans.
"I've really missed her. I think now is a great time for her to come back in her 30s," Duff later said via Instagram. "She's everybody's best friend and I can't wait to go on this next chapter with her, and I hope everyone is as excited as I am."
It's unclear yet if any of the show's other castmates will appear in the new series. Lalaine and Adam Lamberg starred as McGuire's best friends on the show, Miranda and Gordo.
The Disney Channel show originally aired from 2001 to 2004, and The Lizzie McGuire Movie was released in 2003.
A release date for the reboot has not yet been announced, but Disney+ itself will become available in Canada on November 12.
SURPRISE!!! I've been trying to contain this excitement for a loooong time while this has been in the works! I am beyond excited to be home again, back with my girl ♥️...and into her 30's #bringbackbutterflyclips #lizziemcguire #thisiswhatdreamsaremadeof #lizzieforpresident #DisneyPlus #D23Expo . . . . . . Also, If you needed yet another reason to get Disney+ ....the #lizziemcguiremovie will be living there!