A baccalaureate service (or baccalaureate Mass) is a celebration that honors a graduating class from a college, high school, or middle school. The event is typically a Christianity-based interdenominational (ecumenical) service, though it may also be conducted with a particular tradition's liturgy, especially if the academic institution is affiliated with a certain Christian denomination such as the Catholic Church, Lutheran Church, among others.

The service is held within a couple weeks of the graduation/commencement ceremony, perhaps on a Sunday before, the day preceding, or immediately preceding the graduation. Speakers selected tend to be community leaders, faculty members, students, or local religious leaders, and may be elected by the graduating class. Speeches are often intermixed with musical performances, drama, and worship. A modern-day Baccalaureate address generally lasts less than half an hour. In ancient times they could last as long as four hours.

The term baccalaureate may also be applied to similar, graduation-related events at some American high schools, such as presentations of awards and scholarships.