Mount Holyoke College is a private liberal arts women's college in South Hadley, Massachusetts. It is the oldest member of the historic Seven Sisters colleges, a group of elite historically women's colleges in the Northeastern United States.The college was founded in 1837 as the Mount Holyoke Female Seminary by Mary Lyon, a pioneer in education for women. A model upon which many other women's colleges were patterned, it is the oldest institution within the Seven Sisters schools, an alliance of East Coast liberal arts colleges that was originally created to provide women with education equivalent to that provided in the then men-only Ivy League. Mount Holyoke is part of the region's Five College Consortium, along with Amherst College, Smith College, Hampshire College, and the University of Massachusetts Amherst: through this membership, students are allowed to take courses at any other member institution.

Undergraduate admissions are restricted to female, transgender, and nonbinary students. In 2014, it became the first member of the Seven Sisters to introduce an admissions policy that was inclusive to transgender students. However, all graduate programs are open to applicants regardless of gender. Unlike the open curriculums of the other liberal arts schools in the Five College Consortium, Mount Holyoke undergraduates are required to take at least one class each in the humanities, science or mathematics, social sciences, and foreign language, as well as a physical education requirement.

The college's 800-acre (3.2 km2) campus includes the Mount Holyoke College Art Museum, the John Payson Williston Observatory, and a botanic garden, and awards the Glascock Prize annually. Alumni and affiliates include notable poets, authors, feminists, academics, entertainers, scientists, politicians, and civil rights activists, as well as recipients of the Nobel Prize, Pulitzer Prize, Olympic Gold Medal, Rhodes Scholarship, Emmy Award, Golden Globe, and Academy Award.

Mary Mason Lyon (; February 28, 1797 – March 5, 1849) was an American pioneer in women's education. She established the Wheaton Female Seminary in Norton, Massachusetts, (now Wheaton College) in 1834. She then established Mount Holyoke Female Seminary (now Mount Holyoke College) in South Hadley, Massachusetts, in 1837 and served as its first president (or "principal") for 12 years. Lyon's vision fused intellectual challenge and moral purpose. She valued socioeconomic diversity and endeavored to make the seminary affordable for students of modest means.