Helen Abbot Merrill (1864 - 1949) American mathematician, educator and textbook author. Not related to the jazz singer Helen Merrill.

Born in New Jersey of an insurance claims adjuster and a housewife, and raised in Massachusetts, her family tree included colonial settlers. Young Helen’s formal education started at a high school in Massachusetts, and after graduating went to Wellesley College, where she intended to major in Greek and Latin. Unusually, the mathematics faculty at the college consisted mostly of women, including Ellen Hayes, and before completing her first years, Helen Merrill had decided to major in mathematics instead of languages. In 1893 she began teaching at Wellesley while also studying and guest lecturing abroad. In 1920 she was appointed vice-president of the Mathematical Association of America. Upon her retirement from Wellesley, she was given the title Professor Emerita. In addition to textbooks for use at Wellesley, Merrill also wrote as a popularizer a book titled Mathematical Excursions in 1933.