Poweshiek County was named in honor of Chief Poweshiek, a prominent leader of the Fox Tribe, the name being interpreted in treaties as meaning the Roused Bear or the Shedding Bear.

The first courthouse was erected in 1850 on the northeast corner of the square in Montezuma, and the term of court was in 1851. The present courthouse, a larger and better building, was built in the years 1856-1859. It is the second permanent courthouse built in the State of Iowa. In December 1933 work was done to raise the courthouse and this was completed by August 1934. An addition was added to the courthouse from 1982-1983.

The courthouse is located at 302 East Main Montezuma, Iowa 50171 and is open Monday to Friday 8:00 a.m. to 4:00 p.m.