William S. Lind (born July 9, 1947) is an American expert on military affairs and a pundit on cultural conservatism.

Lind graduated from Dartmouth College in 1969 and from Princeton University in 1971, where he received a Master's Degree in history.

He is most widely known as one of the originators of Fourth Generation War (4GW) theory. This theory states that the state has effectively lost its monopoly on warfare, and seeks to address the new challenges posed by this situation. The root of this new phenomenon is the "State's Crisis of Legitimacy," which is also linked to Lind's work at the Center for Cultural Conservatism.