The story unfolds on Christmas Eve, where Kris Kringle, known as Santa Claus, enters a cozy home to deliver gifts and encounters a young girl named Noelle. In a playful manner, Kris asks her to keep his visit a secret. However, it's soon revealed that Noelle is actually his daughter. As Kris shares presents with his family, he gives his son, Nick, a special Santa hat and designates him as his successor. Excited yet somewhat disappointed, Noelle learns that her role will be to spread Christmas cheer, helping her brother fulfill his duties.
Fast forward to the present day, where Noelle, now portrayed by Anna Kendrick, works alongside Nick, who has struggled to embrace his new identity as Santa since their father's passing five months prior. Nick's inadequacies lead to comic mishaps, such as crashing the sleigh, and he finds himself overwhelmed by the responsibilities. During a heart-to-heart, Noelle encourages Nick to take a weekend off to recharge. Seizing the opportunity, he disappears, sparking panic at the North Pole.
As the urgency grows, the festive community decides to appoint Gabe, their tech-savvy cousin, as Santa instead. Feeling blamed, Noelle’s heart sinks while consulting with Polly, the head elf. Their journey quickly escalates as they accidentally send themselves on an unexpected sleigh ride away from the North Pole. Upon landing in Phoenix, Arizona, they find themselves in a legal predicament and must convince the local manager, Helen Rojas, to drop the charges against them, resulting in further complications.
In a twist of fate, Noelle meets a doubtful private investigator, Jake Hapman, while seeking to find Nick. Despite her efforts, Jake remains skeptical of her story. After assisting him with some personal issues involving his son, Alex Hapman, they share humorous and touching moments, expanding their bond as they search for Nick together.
While the North Pole’s situation deteriorates due to Gabe’s unconventional methods of determining who is naughty or nice, Noelle encounters trials and tribulations in her quest. From heartwarming interactions to misunderstandings, she finds herself drawn closer to Jake and Alex, ultimately enlightening them with her unique perspective on life and Santa's legacy.
As tensions rise back at home, Noelle finally manages to locate Nick, convincing him of the urgency to return. Together, they don disguises to bring joy to children at a mall, but even this joy is met with challenges as Gabe’s app has put a damper on their spirits. Facing arrest and further obstacles, Noelle’s resolve is tested as she grapples with feelings of inadequacy.
Just when things seem dire, Jake becomes her unlikely ally, understanding her true intentions. With their combined efforts revealed to Nick, they stage a triumphant return to the North Pole. Ultimately, after a heartfelt declaration of purpose, Noelle takes up the mantle of Santa, dispelling doubts about a woman leading the holiday.
However, her journey to acceptance is not without its stumbles. Through perseverance and support from the community, she finds her footing, redefining what it means to be Santa. In the heartwarming conclusion, Noelle embraces her new role, realizing the true magic of Christmas is about giving, inspiring, and cherishing the people around her. With the North Pole thriving, Noelle reflects on her newfound happiness in making the world brighter for others rather than being centered on herself.
