- a political party in Great Britain, formed about 1830 as a fusion of Whigs and Radicals and constituting one of the dominant British parties in the 19th and early part of the 20th centuries.
- one of the former major political parties in Britain; in 1988 merged with the Social Democratic Party to form the Social and Liberal Democrats; renamed the Liberal Democrats in 1989
- one of the major political parties in Australia, a conservative party, generally opposed to the Labor Party
- one of the major political parties in Canada, generally representing viewpoints between those of the Progressive Conservative Party and the New Democratic Party
- any other party supporting liberal policies