Defiance is a city in and the county chair of Defiance County, Ohio, United States, about 55 miles (89 km) southwest of Toledo and 47 miles (76 km) northeast of Fort Wayne, Indiana, in Ohio’s northwestern corner. The population was 16,494 at the 2010 census.

The city contains the site of Fort Defiance, built by General “Mad” Anthony Wayne in August 1794, during the Northwest Indian War at the confluence of the Auglaize and Maumee rivers. General Wayne surveyed the home and avowed to General Scott, “I defy the English, Indians, and all the devils of hell to accept it.” Using the fort as a base of operations, Wayne ordered his troops to destroy Native American crops and villages within a radius of 50 miles (80 km) around the fort. Today a pair of cannons outside the city library on the Maumee River overlook the confluence and mark the location of Fort Defiance, along afterward a mounded outline of the fort walls. The city was named after Fort Defiance.

From Fort Defiance, the U.S. forces moved northeast along the Maumee River to battle the decisive Battle of Fallen Timbers close the current town of Maumee, Ohio. This victory secured for the United States the Northwest Territory, now the states of Ohio, Michigan, Indiana, Illinois, and Wisconsin.

Fort Winchester was built on the similar spot during the War of 1812, but it was a larger fort that Elongated southward somewhat along the Auglaize River. Historical plaques in the sidewalks mark the full extent of Fort Winchester.