Twenty-year-old Obasi Shaw called the 10-track album Liminal Minds and says it combines "elements of Middle English poetry with issues of racial identity in America".
He says it was inspired by Geoffrey Chaucer's The Canterbury Tales and his own hobby of writing rap music and spoken word poetry.
It took him a year to write.
Last year Kendrick Lamar's To Pimp A Butterfly and Nas' Illmatic were both added to the Harvard Library to signify their cultural significance.
But Obasi's thesis is the first of its kind in the university's history, which was established in 1636.
Senior students at Harvard aren't usually expected to write dissertations but if they want to graduate with honours, they do have to do one.
He got the idea from his mum, who noticed her son writing rap music and performing it at open mic nights on campus.
So instead of submitting an essay or a collection of poems he put together this album.
The project has now had thousands of plays online and explores things like black American identity and the American dream.
Obasi has now uploaded the album to SoundCloud.
"Amateur mixing, unmastered. Will update when I get it professionally done," he writes in the caption.
And although it got him an A-, the 20-year-old will stick to rapping as a hobby.
He'll be starting as an internship as a software engineer at Google later this year.