There is a libertarian school (of which I consider myself to be a member) which wholeheartedly embraces Aristotelian realism and Thomist natural law theory.
The term it uses for a libertarian (really governmentless) society is a "natural order". This natural order is predicated on the principle of subsidiarity rigorously understood and the natural law understanding of the family as the most basic unit of civil society.
St. Thomas' conception of liberty is superior, quite obviously, to Randian and utilitarian notions.
Most FR libertarians are either Randians or "Modal" War-on-Drugs libertarians (as Murray Rothbard called them). I once had a debate on the virtues of polygamy with a libertarian here...he even had it figured out as to what kind of contract would be involved...