Creole in North (west) Metro ATL
If you are looking specifically for Creole, rather than Cajun, I may not be able to help. I still get confused and lump the two together - although I know full well that they are not identical. Just the same, if you are not familiar with these - I would suggest you try them.
Henry's Louisiana Grill, 4935 N Main St, Acworth
AJ's Famous Seafood & Po Boys, 1200 Roswell Rd, Marietta
Gumbeaux's A Cajun Cafe, 6712 E Broad St, Douglasville
There is also a new place about to be opened on Johnson Ferry between Roswell Road and Lower Roswell Road - in the shopping center behind Dunkin' Donuts in East Cobb. I don't recall the name. It is where Merge, and before that Basil's, used to be. The address is 1255 Johnson Ferry Rd, Marietta