Professor Magnolia is the Pokémon Professor of the Galar region, dedicated to researching the Dynamax phenomenon that temporarily enlarges Pokémon. She presents as a slender elderly woman with brown hair and green eyes, typically dressed in a yellow dress under a white lab coat, a purple headband and necklace, beige ballet flats, and glasses. She carries a distinctive cane shaped like a Corviknight.

Her initial mention comes through a Gigantamax news report viewed on a Rotom Phone. She later appears personally when Ash and Goh seek her expertise on unusual Dynamax events in Galar. Her research encompasses formulating theories enabling the creation of Dynamax Bands and identifying Power Spots essential for Dynamax activation. She also investigates the legend of a hero who saved Galar during the ancient Darkest Day crisis using a sword and shield, a mystery intertwined with Dynamax and the legendary Pokémon Zacian and Zamazenta. She conducts this research in collaboration with her granddaughter and assistant, Sonia.

Professor Magnolia expresses concern regarding Chairman Rose's Dynamax energy ambitions, noting a perceived "madness" in his gaze and suspecting his company's potential involvement in triggering dangerous Dynamax incidents outside designated Power Spots. She operates from a motorhome functioning as a mobile laboratory and transport for her team. Her demeanor is professional and perceptive, focused on scientific inquiry and safeguarding the Galar region from the destabilizing effects of uncontrolled Dynamax energy. She eventually steps back from her role, allowing Sonia to succeed her as Galar's primary Pokémon Professor.