The Byrd machine, or Byrd organization, was a political machine of the Democratic Party led by former Governor and U.S. Senator Harry F. Byrd (1887–1966) that dominated Virginia politics for much of the 20th century. From the 1890s until the late 1960s, the Byrd organization effectively controlled the politics of the state through a network of courthouse cliques of local constitutional officers in most of the state's counties.

In the politics of representative democracies, a political machine is a party organization that recruits its members by the use of tangible incentives and that is characterized by a high degree of leadership control over member activity. The machine's power is based on the ability of the boss or group to get out the vote for their candidates on election day.