Joo 주 — Korean last name
Is Joo a Korean last name?
Yes. Joo (Hangul: 주, Hanja: 朱) is a Korean family name recorded in the 2015 South Korean census with 232,063 holders, making it the #33 most common of the 191 surnames counted. Roughly one in every 214 South Koreans is a Joo. It is a well-established name you will meet regularly in Korea and in Korean communities abroad.
How to write Joo in Korean
In Hangul, Joo is written 주. The same Hangul syllable is used by 5 different Hanja (Chinese characters): 朱, 周, 主, 珠, 株. Each character is technically a separate surname with its own clans and ancestry, even though they sound identical and are romanized the same way. The most common by far is 朱.
What does Joo mean?
The character 朱 means vermilion red (朱); also "circumference, Zhou dynasty" (周). As with most Korean surnames, the meaning comes from the Chinese character rather than from the Korean sound, so it says something about how the name was first written down (often a place, a virtue, an object or a Chinese dynasty) rather than describing the family. Koreans rarely think about the literal meaning of a surname in daily life, but it matters for genealogy and for choosing given names that pair well with it.
Major Joo clans (bon-gwan)
Korean surnames are subdivided by bon-gwan — the ancestral hometown of the clan founder. Two people named Joo from different bon-gwan are considered unrelated. The best-known Joo clans are: Sinan Joo, Naju Joo. The place name comes first (for example "Gimhae Kim" means the Kim clan whose founder settled in Gimhae).
How common is Joo?
Joo is common Korean surname. Just above it in the rankings is Ha (233,106) and just below it is Koo (208,550). For comparison, Kim, the most common surname, has 10,689,967 holders. All figures come from Statistics Korea's 2015 Population and Housing Census, which only counts surnames held by five or more people.
Spellings and romanization
Joo is the spelling most Korean families use on passports and in English. The official Revised Romanization (used by the South Korean government since 2000) is Ju, and the older McCune–Reischauer system gives Chu. Other spellings you will see in real life include Joo, Choo, Jou, Zoo, Zhu. The variety exists because Korean passport rules let each family choose its own romanization, so spellings drifted over generations of emigration; in Korean, every one of these is the same 주.
How to pronounce Joo
Joo is pronounced "joo" (주), like the word Jew without the vowel glide.
Is Joo Chinese or Korean?
Both, in a sense — the character is shared, the family is not. Korean surnames were written with Chinese characters for over a thousand years, so nearly every Korean surname has a Chinese (and Vietnamese) reading: 朱 is Zhū in Mandarin and Chu in Vietnamese. A Korean Joo and a Chinese family with the same character are not related; they simply adopted the same character at different times and places. If someone spells their name "Joo" they are almost certainly Korean, because the Chinese and Vietnamese romanizations look different. See our full guide to Korean vs Chinese last names.
Related Korean surnames
Frequently asked questions about Joo
Is Joo a Korean or Chinese last name?
Joo as spelled is Korean (주). The Hanja 朱 is also used as a surname in China and Vietnam, but with different romanizations (Zhū in Mandarin, Chu in Vietnamese). The families are not related.
How many people have the last name Joo?
232,063 people in South Korea had the surname Joo (주) in the 2015 census, or 0.47% of the population. That makes it the #33 most common Korean surname.
How do you write Joo in Korean?
Joo is written 주 in Hangul. In Hanja it is 朱 or 周 or 主 or 珠 or 株, which are separate lineages sharing one pronunciation.
What does the Korean last name Joo mean?
The Hanja 朱 means "vermilion red (朱); also "circumference, Zhou dynasty" (周)". Korean surname meanings come from the Chinese character the name is written with, not from the Korean sound.
Source: Statistics Korea (KOSIS), 2015 Population and Housing Census, surnames by Hangul with five or more holders (total population 49,705,663). Hanja meanings from standard Hanja dictionaries. Check another surname.