On 온 — Korean last name
Is On a Korean last name?
Yes. On (Hangul: 온, Hanja: 溫) is a Korean family name recorded in the 2015 South Korean census with 5,418 holders, making it the #105 most common of the 191 surnames counted. Roughly one in every 9,174 South Koreans is a On. It is a rare surname; most Koreans have never met a On.
How to write On in Korean
In Hangul, On is written 온. Its Hanja (Chinese character) is 溫. Unlike many Korean surnames, On has a single Hanja form, so every On in Korea shares the same character.
What does On mean?
The character 溫 means warm, gentle. 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.
How common is On?
On is rare Korean surname. Just above it in the rankings is Eum (5,604) and just below it is Sagong (4,488). 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
On 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 On, and the older McCune–Reischauer system gives On. Other spellings you will see in real life include Ohn, Eon, Onn, Own, Yon. 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 온.
How to pronounce On
On (온) is pronounced roughly as the Revised Romanization "On" reads, with even stress on each syllable — Korean does not stress one syllable over another the way English does. Vowels are pure and short: "eo" is the "u" in "sun", "eu" is a tight "oo" with unrounded lips, and "ae" rhymes with "day".
Is On 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: 溫 is Wēn in Mandarin and Ôn in Vietnamese. A Korean On 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 "On" 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 On
Is On a Korean or Chinese last name?
On as spelled is Korean (온). The Hanja 溫 is also used as a surname in China and Vietnam, but with different romanizations (Wēn in Mandarin, Ôn in Vietnamese). The families are not related.
How many people have the last name On?
5,418 people in South Korea had the surname On (온) in the 2015 census, or 0.01% of the population. That makes it the #105 most common Korean surname.
How do you write On in Korean?
On is written 온 in Hangul. In Hanja it is 溫.
What does the Korean last name On mean?
The Hanja 溫 means "warm, gentle". Korean surname meanings come from the Chinese character the name is written with, not from the Korean sound.
Is On a rare Korean last name?
Yes. With 5,418 holders it ranks #105 of 191 — well outside the common surnames. See our list of rare Korean last names for others like it.
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.