Forney is located in northwestern Kaufman County at 32°45’5″ North, 96°28’2″ West (32.751521, -96.467225).[6] U.S. Route 80 passes through the city as a four-lane limited-access highway, leading west 20 miles (32 km) to the center of Dallas and east 11 miles (18 km) to Terrell.
According to the United States Census Bureau, in 2010,the city had a total area of 13.2 square miles (34.1 km2), of which 0.02 square miles (0.05 km2), or 0.13%, was covered by water.[5]
Forney is about 4 mi (6 km) southeast of Lake Ray Hubbard, which was formerly known as Forney Lake.