A number of Korean dialects are spoken in Korea and by the Korean diaspora. The peninsula is very mountainous and each dialect's "territory" corresponds closely to the natural boundaries between different geographical regions of Korea. Most of the dialects are named for one of the traditional Eight Provinces of Korea. In the Korean language, only the Jeju dialect is considered sufficiently distinct to be regarded as a separate language.

Korea is a mountainous country, and this could be the main reason why Korean is divided into numerous small local dialects. There are few clear demarcations, so dialect classification is necessarily to some extent arbitrary and based on the traditional provinces. A common classification, originally introduced by Shinpei Ogura in 1944 and adjusted by later authors, identifies six dialect areas:

Hamgyŏng (Northeastern)

Spoken in the Hamgyong Province (Kwanbuk and Kwannam) region, the northeast corner of Pyongan Province, and the Ryanggang Province of North Korea as well as Jilin, Heilongjiang of Northeast China; Russia, Uzbekistan, Kazakhstan of former Soviet Union. Nine vowels: the eight of the standard language plus ö. ^{[citation needed]} Pyongan (Northwestern) Spoken in Pyongyang, Pyongan Province, Chagang Province, and neighboring Liaoning, of China. In North Korea, the standard language known as Munhwaŏ is designated as "Pyongyang Speech." However, the "Pyongan dialect" is still considered a dialect unless it is explicitly designated as part of Munhwaŏ.

The central dialect refers to a dialect generally used in the surrounding areas of Hwanghae Province, Gangwon Province (Kangwon Province), and Chungcheong Province, centering on Seoul and Gyeonggi Province. Depending on scholars, it is divided into the Gyeonggi dialect (Central dialect) and Chungcheong dialect from the beginning, or subdivided into Gyeonggi dialect, Gangwon dialect, Hwanghae dialect, and Chungcheong dialect. The central dialect region is very large, so it is not easy to extract features common to all regions. Among its characteristics, it is more difficult to extract the unique characteristics of the central dialect. For example, which dialect has an intonation as a phonological list is very important in the dialect compartment. Most of the central dialects do not have intonations, but they have intonations in Yeongdong, Gangwon Province, as well as Pyeongchang, Jeongseon, and Yeongwol, the surrounding Yeongseo regions. In the case of vocabulary, the difference is so severe that we do not know how many pieces the central dialect will be divided into. Therefore, the characteristics of the central dialect, which correspond to all regions of the central dialect region, are extremely rare, and if there is such a feature, it is easy to be found in other dialects rather than just the central dialect. Therefore, it may be close to the fact that it is the central dialect that combines the remaining dialects except for other dialects where distinct characteristics are observed, rather than having a specific phenomenon observed only in the central dialect. Since the central dialect consists of sub-dialects that are more heterogeneous than other dialects, it is more likely to be divided into several sub-dialects than any other dialect. Usually, it seems that it can be divided into five sub-dialects.

In any case, the central dialect can be said to be a dialect that can vary in various areas of the dialect depending on the criteria for the dialect compartment. For example, Hwanghae, Gyeonggi, Gangwon and Chungcheong are usually grouped together as the Central dialect region. But, many view that only Hwanghae, Gyeonggi, and Gangwon dialects are included in the central dialect, while Chungcheong dialect is considered as separate dialect.

Gyeongsang (Southeastern)

Spoken in Gyeongsang Province (Yeongnam) of South Korea, including the cities of Busan, Daegu and Ulsan. This dialect is easily distinguished from the Seoul dialect because its pitch is more varied. Six vowels, i, e, a, eo, o, u.^{[citation needed]}