Ozra Amander Hadley was an American politician who served as the acting governor of Arkansas from 1871 to 1873.

In the aftermath of the American Civil War, Pope County, Arkansas experienced a tumultuous seven-month period during the Reconstruction era known as the Pope County Militia War. This time was characterized by political and civil unrest, as four county officials, aided by an unofficial militia, purportedly manipulated county affairs to benefit their own agenda. These officials persistently urged the Arkansas governor to impose martial law in the county, with the aim of exerting greater control over voter registration and the November 1872 election.