Grand Detour is an unincorporated census-designated place in Ogle County, Illinois, United States.

Abraham Joseph Warner established an Episcopal parish in Grand Detour, then regarded as one of the most important settlements in the region.

Soon thereafter, Grand Detour lost most of its residents as the railroad developed towns to the east and south.

In 1909, as Grand Detour's beauty attracted a growing community of artists, Leonard Andrus's son William repaired the church.

The historic church was restored by a nonprofit community group in 1999, and it is now available for public and private events.