I'm a Vietnam passport holder and I live in The United States of America with Permanent Residence (green card holder). My trip will depart from Seattle, Washington for Seoul (going to stay in Seoul for 7 days) then to Vietnam (final destination).
Do I need to obtain a South Korea visa for this trip?
No. From TIMATIC courtesy KLM:
/ 03NOV16 / 2018 UTC
National Viet Nam (VN) /Residence USA (US) Embarkation USA (US) /Transit Korea (Rep.) (KR) Destination Viet Nam (VN)
ALSO CHECK DESTINATION INFORMATION BELOWKorea (Rep.) (KR)
Visa required, except for Passengers with a residence permit issued by USA to nationals of Viet Nam if:
-holding confirmed onward tickets on flights departing within 30 days; when
-arriving on a direct flight from USA, departing to a third country (e.g. USA-ICN-PVG); or
-arriving from a third country, departing to USA (e.g. PVG-ICN-USA).
