The snow queen in Disney's “Frozen” is Elsa. She is the elder daughter of King Agnarr and Queen Iduna, the queen of Arendelle, and Anna's older sister.
Elsa was born with magical powers that let her create ice and snow. After accidentally injuring Anna as a child, Elsa became frightened of her abilities and isolated herself. At her coronation, her powers were revealed, prompting her flight to the North Mountain and the creation of her famous ice palace.
Elsa is loosely inspired by the Snow Queen from Hans Christian Andersen's 1844 fairy tale, but Disney transformed that distant antagonist into a sympathetic central character. A common mix-up is calling Anna the snow queen: Anna is the younger princess who searches for Elsa and helps bring her home.
Elsa's story continues in “Frozen II,” where she investigates the origin of her powers and discovers a deeper connection to nature and the enchanted forest.