John Hailey (August 29, 1835 – April 10, 1921) was a Congressional Delegate from Idaho Territory.He was born in Smith County, Tennessee, and attended the public schools. Of Scottish ancestry, his grandfather, Philip Hailey, and his father, John Hailey, were both natives of Virginia. His father married Miss Nancy Baird, a native of Tennessee, the daughter of Captain Josiah Baird, who had been a captain in the War of 1812.He moved in 1848 to Missouri with his parents, who settled in Dade County.