Princess Marie Alexandra of Baden (Marie Alexandra Thyra Victoria Louise Carola Hilda; 1 August 1902 – 29 January 1944) was a Hessian princess by marriage.

She was the only daughter and elder child of Prince Maximilian of Baden (1867–1929) and Princess Marie Louise of Hanover and Cumberland.

On 17 September 1924, she married her fourth cousin Prince Wolfgang of Hesse (1896–1989).

Princess Marie Alexandra was killed in an attack by the U.S. Army Air Forces during an air-raid on Frankfurt am Main on 29–30 January 1944 during World War II.

She and seven other women, who were aid workers, were killed when the cellar, in which they had taken refuge, collapsed under the weight of the building, rendering Marie Alexandra's body barely recognisable.