The Mule Keys are a group of scattered islets in the Florida Keys in Monroe County, Florida, United States. They are between 3 and 12 miles (5–20 km) west of Key West, separated from it by the Northwest Channel. On the west, they are separated from the Marquesas Keys by 6 mile (10 km) wide Boca Grande Channel. They belong to the outlying islands of the Florida Keys. Administratively, they are unincorporated area of Monroe County. The islets all part of the Key West National Wildlife Refuge. The area of the islets totals 1.07 mi² (2.77 km²), of which 1.02 mi² (2.63 km²) are land area and 0.05 mi² (0.14 km²) inland water bodies (on three of the keys).