Where can I buy a goose?

Can't speak for Atlanta, but up here (Canada) when I am looking for a meat that a supermarket doesn't carry (like goose), I go to the local butcher. My butcher brings in a very good selection, and otherwise usually knows of more sources. Also good places to check are local farmer's markets.

Edit: Adding to an old answer as I've come across another additional thought. Another place that might be worth checking is the farms themselves. It's becoming more common to have farms that sell directly to consumers. Around here there's quite a few. A quick Google for "goose farm yourlocation" might be a place to start.

There is an international food company call ajc that sells frozen birds and one of the offices is located in Atlanta. A friend of my actually bought a goose from them two years ago. This company usually sells frozen foods. If you go to their website I linked above there may be a way to get a bird before its frozen, but I'm not sure. They have goose for sure though, everyone who ate it said it was great. Hope this helps.

D'Artagnan is a very reputable gourmet meat purveyor here in the US, and they sell over the Internet. They sell very high quality geese, however, they're a bit expensive.

You might try the Dekalb Farmer's Market (in Atlanta, GA) or Super H Mart, depending on where you are at. I don't specifically recall if they sell geese either place, but it seems likely. At the Dekalb FM, they would be in with the "other" meats near the poultry.

I'd also second finding a butcher, if there is one nearby, but most of the ones I am aware of are pretty basic low end places.

Edit: I just called, and the Dekalb Farmer's Market does sell geese! I still don't know about Super H Mart, though.

I buy things like that at a local farmer's market - that where I got the duck for today's dinner. They almost always have a butcher or two that can get anything you want.