Sophia Dorothea of Brunswick and Luneburg (Celle line) (15 September 1666 – 13 November 1726) is the wife and cousin of George Louis, Elector of Hanover, later George I of Great Britain, and mother of George II through an arranged marriage of state, instigated by the machinations of Duchess Sophia of Hanover.

She is best remembered for her alleged affair with Philip Christoph von Königsmarck that led to her being imprisoned in Castle of Ahlden for the last thirty years of her life.