Jerome County was created on February 8, 1919 from the parent Counties of Gooding, Minidoka and Lincoln. In the 1880’s what is now Jerome County was part of Alturas County, which no longer exists.

Jerome County is believed to be named after Jerome Kuhn, son of WS Kuhn who had purchased North Side property from Frank Buhl, and planned on building a town site on the North Side. Others believe Jerome was named after Jerome Hill who was commissioned by Kuhn to find a suitable area for a town site. Traveling all day Jerome Hill and his group found themselves lost in the lava and sagebrush so the group made camp for the night. Morning brought a wondrous view of the Sawtooth Mountains to the North and Twin Falls to the South and all agreed that they had found the right site. Markers were placed at the location and Jerome town site began her legacy.

Jerome County consists of the small farming communities (town sites) of Eden, Hazelton, and Jerome, with Jerome being the County Seat.

The Minidoka Relocation Camp, one of ten Japanese American internment camps set up during World War II, was located in Jerome County, six miles north of Eden in a small community named Hunt. Small remnants of the camp can still be seen today.

Jerome has the distinction of being the 43rd County in the 43rd State of the United States of America.