The county is bordered on the north by Iroquois County.

Vermilion County, out of which Iroquois County was originally formed, lies to the south.

In 1855 they moved again, this time to Iroquois County, Illinois, where Darrough would live the rest of his life.

After the war, he returned to Iroquois County where he resided until his death at age 79.

In 1937, she became a judge in Iroquois County before being elected to the House of Representatives in 1938.

Chase was born in Iroquois County, Illinois.

Claytonville is an unincorporated community in Iroquois County, Illinois, United States.

Attempts in the 20th century to reintroduce the greater prairie chicken to northeastern Iroquois County failed.

She served as county judge of Iroquois County, Illinois, in 1937.

Watseka is a city in and the county seat of Iroquois County, Illinois, United States.