Wlliams holds a bachelor's degree in economics from California State University at Los Angeles (1965) and a master's degree (1967). He also received his Ph.D. from the University of California, Los Angeles in 1972. Since being a graduate student at UCLA, he has been a friend of fellow African American economist and columnist Thomas Sowell. Correspondence between Sowell and Williams appears in the 2007 "A Man of Letters" by Sowell. Williams has been a Professor of Economics at George Mason University since 1980, and chairman of that University's Economics department from 1995 to 2001.

He has previously been on the faculty of Los Angeles City College, California State University - Los Angeles, Temple University, and Grove City College. Williams was awarded an honorary degree at Universidad Francisco Marroquin.

Williams has written hundreds of articles and his syndicated column is published weekly in approximately 140 newspapers across the United States, as well as on several web sites by Creators Syndicate.

As an economist, Williams often speaks and writes in favor of free market economics and against socialist systems and government intervention. He has said "That's a challenge I love: making economics fun and understandable."

Williams supports legalization of selling one's own bodily organs on the grounds that it increases the supply of organs for transplant. He also makes the libertarian argument that the true proof of whether or not an individual owns something is whether or not he/she has the right to sell it. If selling organs is illegal, he says, then, consequently, individuals do not own their own bodies.

He is also a critic of the minimum wage and affirmative action, believing that both practices are detrimental to both blacks and liberty. Williams especially emphasizes his belief that racism and the legacy of slavery in the United States are overemphasized as problems faced by the black community and do not adequately explain the situation blacks face today.

Holding libertarian viewpoints, Williams criticizes gun control as endangering the innocent and failing to reduce crime. Williams opposes anti-discrimination laws in the private sector on the libertarian grounds of freedom of association.

He said, "I praise lassez-faire capitalism as being the most moral and most productive system man has ever devised. Capitalism is relatively new in human history. Prior to capitalism, the way people amassed great wealth was by looting, plundering and enslaving their fellow man. Capitalism made it possible to become wealthy by serving your fellow man."

He has gone on record as advocating the Free State Project in at least two columns and once on television. The Williams endorsement correlated with the largest single membership jump in the first 5000 phase of the project, a jump even higher than the results of the project being Slashdotted. He also believes in the right of U.S. states to secede from the union as several states attempted to do during the Civil War. Williams has supported or been sympathetic toward various secessionist ideas in his writings."As I got a little older I had it mostly polished when I was in college in terms of the ideas of liberty. And also I must have read Thomas Paine’s Common Sense I don’t know how many times. At least twenty-thirty times, and that kind of instilled some radical ideas in me as Thomas Paine was trying to instill in the colonists. Affirmative action has led to, I believe, many Black people expecting favors from the system and not working as hard as they otherwise would, that is if you know that you can get into college because of affirmative action...or some people call it diversity nowadays...well then why work as hard in high school? So it might undermine some of the spirit of people. And I think that the basic premise of those who advocate affirmative action is that the problems that Black Americans face today are the result of racial discrimination."

Williams serves on the boards of a number of non-profit organizations, including the Bruin Alumni Association.

Cartoonist Bruce Tinsley, in his comic strip Mallard Fillmore, launched a campaign to draft Williams for the Republican presidential nomination in the 2008 United States presidential election. Mallard Fillmore Although Williams initially stated that he wouldn't completely rule out the possibility, he ultimately decided against such a run, and endorsed Ron Paul.

Williams and his wife Connie were married from 1960 until her death on December 29, 2007. They have one daughter, Devyn, who resides in Los Angeles, California. Williams is a cousin of former NBA player Julius Erving.