Eugene Jerome Hainer (August 16, 1851 – March 17, 1929) was an American Republican Party politician. Born in Pécs, Hungary in 1851, he immigrated to the United States with his parents settling in Columbia, Missouri, in 1854. He later moved with them in 1861 to the Hungarian settlement of New Buda, Iowa founded by George Pomutz. He spent his childhood on a farm near Garden Grove, Iowa. Was educated in Garden Grove Seminary school and then in the Iowa Agricultural College. He graduated from the law department of Simpson College in Indianola, Iowa in 1876 and was admitted to the bar in the same year.