A warlord is an individual who exercises military, economic, and political control over a region, often within a country without a strong national government, through usually informal or illegal coercive control over the local armed forces. Warlords have existed throughout much of history, albeit in a variety of different capacities within the political, economic, and social structure of states or ungoverned territories. The term is often applied in the context of China around the end of the Qing Dynasty, especially during the Warlord Era. The term can also be used for any supreme military leader.

The Warlord Era was a period in the history of the Republic of China when control of the country was divided among former military cliques of the Beiyang Army and other regional factions from 1916 to 1928.