The Whigs (with the Tories) are often described as one of two political parties in England and later the United Kingdom from the late 17th to the mid 19th centuries. It is more accurate to describe the original two ideas as loose groupings, or more precisely, tendencies. While the Whigs' origin lay in constitutional monarchism and opposition to absolute rule, both might be termed conservative by modern parameters. Party politics did not begin to coalesce until at least 1784, with the ascension of Charles James Fox as the leader of a reconstituted "Whig" party, ranged against the governing party of the new "Tories" under William Pitt the Younger.

The Whig party slowly evolved during the 18th century. In general terms, the Whig tendency supported the great aristocratic families and non-Anglicans (the "dissenters", such as Presbyterians), while the Tories supported the Anglican Church and the gentry. Later on, the Whigs drew support from the emerging industrial interests and wealthy merchants, while the Tories drew support from the landed interests and the British Crown. The Whigs were originally also known as the "Country Party" (as opposed to the Tories, the "Court Party"). By the first half of the 19th century, however, the Whig political programme came to encompass not only the supremacy of parliament over the monarch and support for free trade, but the abolition of slavery, and, significantly, expansion of the franchise (suffrage). Eventually the Whigs would evolve into the Liberal Party (whilst the Tories became the Conservative Party).