Originally Posted by Garbageman

Asiana (OZ) is the only *A carrier that flies to CJU (I live here at the moment). They have once or twice a day flights from ICN, but the most common route is from GMP, so you'll have to change airports in Seoul - budget between 30 minutes and an hour to do the transfer by either bus or train (and then check in at GMP an hour before your flight). GMP-CJU flights go several times an hour all day, so you can usually ask to get moved to an earlier flight if you make it to GMP early.

Other alternatives are to fly AC to PVG and then transfer to China Eastern, fly to HKG and then transfer to Dragonair, fly to PEK and transfer to Korean Air, or fly to NRT and transfer to Korean Air (but you'll have to overnight at NRT as the KE NRT-CJU flight leaves in the morning). There are no other *A alternatives.

I don't usually like booking two separate tickets, but in this case, I'd really recommend that you book the GMP-CJU portion separately as it'll be far cheaper. You can book and pay with foreign credit cards on OZ's site.

If you have *G status, you're pretty likely to get upgraded GMP-CJU on OZ if your aircraft has a business cabin (many don't that fly this route) - I'm at about 50% for this. No extra service, just a bigger seat.

Let me know if you have any other questions about Jeju!