Castle Gresley is a village and civil parish about 1.75 miles southwest of the centre of Swadlincote in South Derbyshire, England. The population was 1,566 at the 2001 Census increasing to 1,799 at the 2011 Census. The village is about 1 mile west of the village of Church Gresley. Castle Gresley has the remains of a motte and bailey castle known locally as Castle Knob.