Human beings, each considered as a single actor within society
- Salerno, Joseph - American economist of the Austrian school, professor at Pace University
- Say, Jean-Baptiste - 18th-19th century French economist
- Schoolland, Ken - Professor of Economics and Political Science, author
- Schulman, J. Neil - American science fiction writer, winner of Prometheus Best Novel and Hall of Fame awards
- Schumpeter, Joseph - 20th century Austrian economist
- Sciabarra, Chris Matthew - Politics scholar at New York University, editor of The Journal of Ayn Rand Studies
- Scientists - Researchers of the natural sciences
- Senior, Nassau William - Nineteenth century English economist
- Sennholz, Hans - German-American economist of the Austrian School
- Shaffer, Butler - Professor of law at Southwestern University
- Sidney, Algernon - 17th century British Member of Parliament
- Simon, Julian - Professor of Business Administration, author
- Sirico, Robert - Co-founder and President of the Acton Institute for the Study of Religion and Liberty
- Skousen, Mark - Author, investment advisor, professor of Economics
- Smith, Adam - Eighteenth century Scottish economist, author of The Wealth of Nations
- Smith, George H. - Writer, author of Why Atheism?
- Smith, Vernon L. - 2002 Nobel Prize winner in Economic Sciences
- Sobran, Joseph - Nationally syndicated columnist, past Senior Editor for National Review
- Sociologists - Students of society and social institutions
- Sowell, Thomas - Author, syndicated columnist, fellow at the Hoover Institution
- Spencer, Herbert - 19th century English philosopher
- Spooner, Lysander - Lawyer, abolitionist, entrepreneur, legal theorist and political radical
- Stigler, George - 20th century American economist, winner of the 1982 Nobel Prize in economics
- Stossel, John - Host of "Stossel" show on Fox Business channel and former ABC News correspondent for the "20/20" newsmagazine
- Stromberg, Joseph R. - Historian, research fellow at The Independent Institute
- Sullum, Jacob - Senior editor of Reason, nationally syndicated columnist
- Sumner, William Graham - Nineteenth century professor of political and social science at Yale University
- Szasz, Thomas - Psychiatry professor and author