Marie J. Mergler (May 18, 1851 – May 18, 1901) was a 19th-century German-born American physician, surgeon, and medical writer. She began practice in Chicago in 1881, doing general practice at first and then limiting herself to obstetrics and gynaecology. In the latter, she acquired great skill as a surgeon, and in this field stood among those at the head of her profession in what was then considered to be the northwestern United States. She served her Alma Mater as lecturer, professor, secretary and Dean. She held several hospital positions as consultant or on the attending staff.