Lonoke County is a county located in the U.S. state of Arkansas. As of the 2010 census, the population was 68,356. The county seat is Lonoke, and the largest city is Cabot. Lonoke County is Arkansas's 70th county, formed on 16 April 1873. Its name originates from a "lone oak" tree that stood on the site of the present county seat; the red oak tree was used as a local landmark by a railroad surveyor.