Mercersburg Academy is an independent, coeducational boarding school for grades 9-12 located in Mercersburg, Pennsylvania, United States. The school's mission is: "[to] prepare young men and women from diverse backgrounds for college and for life in a global community."

On March 31, 1836, the Pennsylvania General Assembly granted a charter to Marshall College to be located in Mercersburg. Dr. Frederick Augustus Rauch came from Switzerland to be the first president of the college under the sponsorship of the Reformed Church in America. Dr. Rauch served as president from 1836 until 1841. His successor in the position was John Williamson Nevin who served until 1853, when Marshall College joined with Franklin College in Lancaster, Pennsylvania to become Franklin & Marshall College. At this time, the preparatory department of Marshall College became known as Marshall Academy which later changed to Marshall Collegiate Institute. In 1865, the name was again changed to Mercersburg College, under whose charter the school continues to operate. The historic tie to the church continues through Mercersburg's membership in the Council for Higher Education of the United Church of Christ.