In United Kingdom politics, the term Blairite refers to a personal and/or political supporter of Tony Blair, Leader of the Labour Party from 1994-2007 and Prime Minister from 1997-2007.

Politically, Blair has been identified with the introduction of quasi-markets into public services, an interventionist and Atlanticist foreign policy, and support for stronger law enforcement powers. In the early years (circa 1994-1997), Blairism was also associated with support for European integration and particularly British participation in the European single currency, though this waned after Labour took office.

The term is used in particular in contrast to Brownite, to identify those within the Labour Party who prefer Gordon Brown's leadership to that of Blair. However, with Blair and Brown typically in agreement on most political issues (from Iraq to public sector reform), commentators have noted that "the difference between Brownites and Blairites … is more tribal than ideological" . This is believed to stem from a personal disagreement between Blair and Brown over who should have run for the leadership following the death of John Smith in 1994: though Brown was originally considered the senior of the two, he waited until after Smith's funeral to begin campaigning by which point Blair had gathered too much momentum to be beaten.

For a long time, there has been a great deal of discussion in British politics about the Blairite legacy. This has intensified since September 2006, when Blair announced his intention to resign within a year, and especially since May 2007, when he said he would resign as Prime Minister on June 27, 2007. While centrists such as Gordon Brown and David Cameron claim that Blairism is safe in their hands, critics on the left (e.g. John McDonnell) and right (e.g Norman Tebbit) dispute its value to British society. Others have even speculated that, if the Blairite coalition is to be seen as essentially one of pro-market anti-Conservatives, the Liberal Democrats could even be its ultimate inheritors.