K
- Peter Kapetan, Broadway actor, singer, dancer 1956–2008 (graduated 1974)
- Marsha Kazarosian, nationally known trial attorney (graduated 1974)
- Charles W. Kendall, U.S. Representative, lawyer, newspaper editor
- John F. Kennedy, Jr., publisher, son of former U.S. president John F. Kennedy (graduated 1979)
- Patrick J. Kennedy, Former U.S. Representative from Rhode Island (graduated 1986)
- Prince Rahim Aga Khan, Son of the Aga Khan IV (graduated 1990)
- Victor K. Kiam, businessman and owner of the New England Patriots (graduated 1944)
- Brian Kibler, an American game designer currently working with Gamer Entertainment. Professional Magic: the Gathering Player
- Tracy Kidder, author (graduated 1963), Pulitzer Prize for Soul of the New Machine (1982)
- Earl Killian, computer scientist with 25+ patents (graduated 1974)
- William S. Knowles, winner of the Nobel Prize in Chemistry in 2001 (graduated 1935)
- Lawrence Kohlberg, psychologist (graduated 1945)
- Chris Kreider, center for the New York Rangers, Boston College hockey player (graduated in 2010)
Read more about this topic: List Of Phillips Academy Alumni