There are various names of Korea in use today that are all derived from those of ancient Koreanic kingdoms and dynasties. The choice of name often depends on the language, whether the user is referring to either or both modern Korean countries, and even the user's political views on the Korean conflict.

The name Korea is an exonym, derived from Goryeo or Koryŏ. Both North Korea and South Korea use the name in English. However, in the Korean language, the two Koreas use different terms to refer to the nominally unified nation: Joseon or Chosŏn (조선; 朝鮮) in North Korea and Hanguk (한국; 韓國) in South Korea.

The earliest records of Korean history are written in Chinese characters called hanja. Even after the invention of hangul, Koreans generally recorded native Korean names with hanja, by translation of meaning, transliteration of sound, or even combinations of the two. Furthermore, the pronunciations of the same character are somewhat different in Korean and the various Korean dialects, and have changed over time.

For all these reasons, in addition to the sparse and sometimes contradictory written records, it is often difficult to determine the original meanings or pronunciations of ancient names.

Until 108 BC, northern Korea and part of Manchuria were controlled by Gojoseon. In contemporaneous Chinese records, it was written as 朝鮮, which is pronounced in modern Korean as Joseon (조선). Historically, these characters have been read in the Korean language as 됴션 Dyosyen; 조선 Joseon is a very recent spelling, reformed to reflect recent changes in the phonology of the Korean language. The prefixing of Go- (古), meaning "old" or "ancient," is a historiographical convention that distinguishes it from the later Joseon dynasty. The name Joseon is also now still used by North Koreans and Koreans living in China and Japan to refer to the peninsula, and as the official Korean form of the name of Democratic People's Republic of Korea (Joseon). Cognates of 朝鮮 Joseon are also used in many Asian languages, such as Japanese, Vietnamese, and Chinese, to refer to the Korean Peninsula. ^{[citation needed]}

Possibly the Chinese characters phonetically transcribed a native Korean name, perhaps pronounced something like "Jyusin". Some speculate that it also corresponds to Chinese references to 肅愼 (숙신, Suksin (ethnic group)), 稷愼 (직신, Jiksin) and 息愼 (식신, Siksin), although these latter names probably describe the ancestors of the Jurchen people.

Other scholars believe 朝鮮 was a translation (like Japanese kun'yomi) of the native Korean Asadal (아사달), the capital of Gojoseon: asa being a hypothetical Altaic root word for "morning", and dal meaning "mountain", a common ending for Goguryeo place names (with the use of the character 鮮 "fresh" to transcribe the final -dal syllable possibly having been based on the pronunciation of the ancient ancestor of Middle Korean dɔl- > Modern Korean 달 dal- "sweet").

An early attempt to translate these characters into English gave rise to the expression "The Land of the Morning Calm" for Korea, which parallels the expression "The Land of the Rising Sun" for Japan. While the wording is fanciful, the essence of the translation is valid.^{[citation needed]}