Ozra Amander Hadley (June 30, 1826 - July 18, 1915) was appointed as acting governor of the U.S. state of Arkansas, having served from March 1871 until 1873. A native of New York, Hadley moved in 1855 to Minnesota, where he was a farmer. After the American Civil War, he relocated to Arkansas, where he became a merchant.
During the Reconstruction era, he was elected to the Arkansas State Senate, in which he served from 1869 to 1871. He was appointed as governor in 1871 after a political compromise achieved the resignation of Powell Clayton, a controversial figure associated with the Brooks-Baxter War. Hadley later moved to New Mexico, where he owned a ranch.
He was born in Cherry Creek, New York, and was educated in the public schools. He attended Fredonia Academy, now State University of New York at Fredonia.
While in Minnesota, Hadley became active in local politics and was appointed county auditor.
In 1865, he settled in Little Rock, where he went into business as a merchant.
Hadley was elected by the Reconstruction state legislature as a Republican to serve in the Arkansas Senate from 1869 to 1871; he was elected president of the Senate in 1871. In 1871, as part of a political compromise (see: Brooks-Baxter War), he was appointed as Acting Governor of Arkansas after Powell Clayton resigned. During his term, he sided with the Radical Republicans and denied assistance to re-enfranchised whites.{{<--Expand and explain-->}} Hadley left office in 1873.