In the cheerful town of Whoville, the Whos are brimming with excitement for their favorite holiday, Christmas. Unbeknownst to them, just north of their town, lives a green, reclusive creature known as the Grinch, who harbors an intense dislike for the holiday and the incessant cheer of the Whos. With a heart "two sizes too small," the Grinch has spent years away from Whoville, brooding over his past humiliations and the relentless joy of the townsfolk below. The mere thought of Christmas spirals him into anger, and he begrudgingly endures the holiday season from his mountaintop home with only his dog, Max, for company.

One fateful day, a young Who girl named Cindy Lou becomes intrigued by the Grinch's absence from the town's communal merriment. Her curiosity leads her to investigate the true reasons behind his hatred for Christmas. Determined to spread holiday cheer to every corner of Whoville, including the Grinch's cold, lonely abode, Cindy Lou sets out to befriend the Grinch, inviting him to partake in the town's Christmas festivities. As the celebration approaches, the Grinch's bitterness reaches its peak, devising a plan to halt the holiday by descending upon Whoville and strip it of all traces of Christmas, thus silencing the Whos' cheer once and for all.