The donation from philanthropist Giles "Gil" Kemp and his wife, Barbara, comes as the elite liberal arts school prepares to celebrate its 150th anniversary next year.
"Gil is among our most passionate, articulate, and loyal ambassadors and understands well where Swarthmore's core values lie and how we can best support them," college President Rebecca Chopp said in a statement.
Most of the gift - $8 million - will be used to create a need-based scholarship program for students interested in global leadership. Swarthmore costs about $56,000 a year.
Another $7 million will go to improve community space by renovating 83-year-old Clothier Hall. The remaining $5 million is pledged for general college support.
Kemp, an alumnus whose business interests have included direct marketing and home furnishings, also serves as chairman of Swarthmore's board of managers.
"The education I received and the experiences I had at Swarthmore literally changed my life and launched my career," Kemp said in a statement.
The Kemps' donation comes less than three months after alumnus Eugene Lang gave the school $50 million, the largest gift ever received by the college.
About 1,500 students attend Swarthmore, in suburban Philadelphia. It was co-founded in 1864 by Lucretia Mott, a prominent Quaker abolitionist and activist for women's rights.
