Seven percent are "consistent" libertarians, while 15 percent lean libertarian, according to the survey.
The poll found that libertarians tend to be non-Hispanic white, young and male. Ninety-four percent are non-Hispanic whites, 62 percent are below age 50 and 68 percent are men.
Libertarians also typically identify with the GOP -- 45 percent are Republicans while five percent are Democrats.
The Public Religion Research Institute surveyed a random sample of 2,317 adults online Sept. 21-Oct. 3 and had a margin of error of plus or minus 2.5 percentage points.