Founder's Day is a day of celebrating the founding of Mount Holyoke Female Seminary and honoring Mary Lyon and her living legacy. Held on the Sunday nearest to November 8, the date the Seminary opened in 1837, it is a day for reflection and respect. Begun by President Elizabeth Storrs Mead in 1891, this is one of Mount Holyoke College's oldest traditions.

Early Days - Originally this day involved students and professors gathering around the grave site in full academic regalia. Flowers or a wreath were laid on the grave marker to commemorate Mary Lyon. Inside Abbey Chapel, Founder's Day was marked by speeches and lectures given by a wide variety of speakers, from professors to guest lecturers to a former United States president. Honorary events were often saved for the Founder's Day ceremonies. Over various years on Founder's Day, the laying of many cornerstones of new buildings and the dedications of multiple buildings were incorporated into of the ceremonies. Sometimes the talks were thematic, as seen in 1928 when Founder's Day's lectures made up an Emily Dickinson themed conference. Former United States President Taft gave an address once. Honorary degrees were also often bestowed upon this day. Except for 1916, when Founder's Day had to be cancelled due to a polio epidemic, this has been a truly annual event.

Additions and Evolution - In the 1920s, early morning ice cream became a part of the Founder's Day tradition. The laying of the flowers or wreaths continued until recently, when the gathering around the grave site became a more casual observance. Lectures still continue, though with less of the original pomp and circumstance.