Libertarian League was a name used by two American anarchist and libertarian socialist organisations during the twentieth century.
The first Libertarian League was founded in Los Angeles between the two World Wars. It was established mainly by Cassius V. Cook, Charles T. Sprading, Clarence Lee Swartz, Henry Cohen, Hans F. Rossner and Thomas Bell.
The second Libertarian League was founded in New York City in 1954 as a political organisation building on the Libertarian Book Club. Members included Sam Dolgoff, Russell Blackwell, Dave Van Ronk, Enrico Arrigoni and Murray Bookchin. This league had a narrower political focus than the first, promoting anarchism and syndicalism. Its central principle, stated in its journal Views and Comments, was "equal freedom for all in a free socialist society". Branches of the League opened in a number of other American cities, including Detroit and San Francisco. It was dissolved at the end of the 1960s.