This is a list of notable graduates of Siena College in Loudonville, New York.

• Steven Lamy, professor of international relations and Vice Dean for the College of Letters, Arts, and Sciences at the University of Southern California
• Wolf Wolfensberger, professor and author of Principle of Normalization (people with disabilities) and Social role valorization

• William J. Kennedy, 1984 Pulitzer Prize for Fiction winner
• Len Roberts, award-winning poet
• Ron Vawter, actor and a founding member of The Wooster Group
• Wendy Moniz, television actress

• Francis Bergan, former Presiding Justice of the New York Court of Appeals
• Michael Botticelli, former director of the Office of National Drug Control Policy
• Charles R. Boutin, member of the Maryland House of Delegates
• Anthony Brindisi, class of 2000, United States Representative from New York, 22nd Congressional District of New York from 2019 to 2021
• Constantine George Cholakis, former Judge of the United States District Court for the Northern District of New York
• Michael Dempsey, Acting Director of National Intelligence, Deputy DNI for Intelligence Integration^[1]
• Mae D'Agostino, United States District Judge for the United States District Court for the Northern District of New York
• George Deukmejian, 35th Governor of California
• Michael C. Finnegan, former Counsel to the Governor of New York during the George Pataki Administration
• Chris Gibson, former United States Representative
• Wayne LaPierre, gun rights advocate; Executive Vice President and CEO of the National Rifle Association
• John McEneny, member of the New York State Assembly and Albany County Historian
• Jack Quinn, former United States Representative from New York; President of Erie Community College
• Gerald B. H. Solomon, former United States Representative from New York
• Henry F. Zwack, Justice of the New York Supreme Court, 3rd Judicial District

• Jack Cashill, author and journalist
• Erich Hartmann, international award-winning photojournalist; former President of Magnum Photos
• David Hepp, award-winning journalist and creator of Inside Albany

• Harry Flynn, Archbishop Emeritus of Saint Paul and Minneapolis
• Roberto González Nieves, Archbishop of San Juan

• Matt Brady, coach for several men's college basketball teams
• Tim Christman, Major League Baseball relief pitcher
• Marcus Faison, professional basketball player
• Matt Gage, Major League Baseball pitcher with the Toronto Blue Jays
• Jeff Hafley, head football coach at Boston College
• Billy Harrell, Major League Baseball infielder
• Kenny Hasbrouck, professional basketball player
• Gary Holle, Major League Baseball first baseman
• John Lannan, Major League Baseball pitcher
• Michael E. Long, men's basketball coach at The College of Saint Rose
• Jack McClinton, professional basketball player
• Elisa Mevius, German basketball player and Olympic gold medalist in 3x3 basketball
• Charlie Taaffe, football coach at the University of Central Florida
• Edwin Ubiles, professional basketball player

• Olivia Benson, the main character in the long-running NBC police procedural Law and Order: Special Victims Unit, attended Siena College.