The county is named for Henry W. Grady, editor of the Atlanta Constitution and noted orator.

Grady County's western border, from Whigham south, and all of its southern border, is located in the Lower Ochlockonee River sub-basin of the same Ochlockonee River basin.

Finally, a very small chunk of the county's southeastern portion, bisected by U.S. Route 319, is located in the Apalachee Bay-St. Marks sub-basin of the Ochlockonee River basin.

[5] Grady County includes part of the Red Hills Region.

As of the 2020 United States census, there were 26,236 people, 9,136 households, and 6,320 families residing in the county.