If you are planning to visit Seoul, you may need a visa depending on your home country and purpose of visit. Here is how to find out if you need a visa.
FOR TOURISTS AND TEMPORARY VISITORS
Foreign visitors who visit to travel to South Korea must have a valid passport and obtain a visa prior to arrival. Citizens of 84 countries, including the United States of America, Canada, Australia, and United Kingdom, are part of a waiver agreement.
This means that citizens of these countries do not need to obtain one prior to their arrival. It will be automatically be given at the airport when passing through customs.
The length of these single entry tourist visas varies from 30 to 180 days, depending on the nation. Citizens of the United States may stay for 90 days. Those who wish to extend their stay or need to enter multiple times, need to visit a local immigration office prior to the expiration date. If approved, extensions are usually valid for another 90 days. You may also apply for an extension in case of an emergency or unforeseen circumstances such as a medical emergency or flight cancellation.
There are other situations when travelers are exempt. This includes most travelers connecting to flights bound for another country, Japanese tourists, Chinese tourists bound for Europe, frequent visitors, United Nations members, APEC Business Travel Card holders, and all countries under exemption agreements.
To find out if your country is part of the waiver agreement, then please visit http://www.visitkorea.or.kr/enu/GK/GK_EN_2_1_1.jsp where you can view a list of requirements for each country.
FOR WORK PURPOSES
All foreign visitors who wish to work in Korea must obtain a work visa prior to arrival from a Korean embassy or consulate in their home country. This process usually takes one to two weeks and can be valid for up to three years from the date of approval. Sponsorship of an employer in Korea may be required.