Human beings, each considered as a single actor within society
- Kauffman, Bill - Author, associate editor of The American Enterprise
- Kelley, David - Founder and Executive Director of The Objectivist Center
- Kennedy, John F. - Thirty-fifth President of the United States
- Kirzner, Israel - Professor of Economics at New York University
- Klausner, Manny - American lawyer, co-founding editor of Reason magazine
- Knight, Frank - 20th century American economist of the Chicago School
- Konkin III, Samuel Edward - Proponent of agorism and author of the New Libertarian Manifesto