Originally Posted by
agp423
She has a US green card and a Chinese passport. We'll be flying PEK-ICN-JFK, spending the night at ICN. From what I gather she can do transit without visa if she has proof that her final destination is US. But I will call the consulate to make sure. Thanks all for the help!
I have traveled SFO-ICN-CGQ (Changchun, China) route multiple times with a one-night lay-over at ICN. I did not have any S. Korean visa and I do not even have a green card. As long as you can show you are confirmed to continue to US and have the entry permit (in your case the green card), they will let you through the immigration.
What's even better? The validity of the stamp by the Korean immigration always is one month! I've never stayed beyond one night though...