However, there's really not many jobs for foreigners except as English teachers. If you want a non-teaching job, you'll probably either need to be near-fluent in Korean, or you need to have a special skill-set that can compensate for your lack of fluency (high-level STEM or IT knowledge, or fluency in a high-demand exotic language like arabic). The only jobs, other than english teachers, where English alone can land you a job is overseas marketing, or something specific to the ex-pat community (owning a bar, for example). However, in both those cases you should have some experience in Korea first.
I would suggest to first go there as a teacher or as a student, get a feel for the country, then explore non-teaching opportunities. You're definitely not going to get a non-teaching job right off the airplane.
Source: 4+ years in Korea.