This list of Cornell University alumni includes notable graduates, non-graduate former students, and current students of Cornell University, an Ivy League university whose main campus is in Ithaca, New York.

As of 2024, Cornell has over 250,000 living alumni. Since the university's founding, its alumni have included 25 recipients of National Medal of Science and National Medal of Technology and Innovation combined, 38 MacArthur Fellows, 34 Marshall Scholars, 31 Rhodes Scholars, 249 elected members of the National Academy of Sciences, 201 elected members of the National Academy of Engineering, and over 190 heads of higher learning institutions.

Cornell is the only university in the world with three female winners of unshared Nobel Prizes among its graduates; Cornell alumni Pearl S. Buck, Barbara McClintock, and Toni Morrison each were unshared recipients of the prize. Many alumni maintain university ties through the university's homecoming. Its alumni magazine is Cornell Magazine. In Manhattan, the university maintains the Cornell Club of New York for alumni. In 2005, Cornell ranked third nationally among universities and colleges in philanthropic giving from its alumni. Alumni are known as Cornellians, many of whom are noted for their accomplishments in public, professional, and corporate life.

In contemporary culture, fictional alumni have been portrayed in several films, television shows, and books. In television, Andy Bernard on The Office (2005 to 2013), Gary Walsh on Veep (2012 to 2019), Tom Kirkman on Designated Survivor (2016 to 2018), Mitchell Pritchett on Modern Family (2009 to 2020), Tom Wambsgans on Succession (2018 to 2023), Shane Patton on HBO's The White Lotus (2021 to present), and Deborah "DJ" Vance Jr. on Hacks (2021 to present) are each Cornell University alumni. In films, Christina Pagniacci in Any Given Sunday (1999) and Natalie Keener in Up in the Air (2009) are both Cornell alumni.