Ong
A rare surname with several possible roots, most likely tied to a place-name or an abbreviated older English/Continental form.
The #3,704 most common surname in the United States (2010 Census) — about 1 in every 32,215 Americans shares it.
Etymology
The historical evidence for Ong is thin, and the old surname dictionaries mostly mention it only in passing. It may be a shortened or altered form of a place-based name such as Onley/Onley-type names, or it may reflect a continental surname pattern like Dutch or German names built on forms such as Unger/Onger. Because the sources do not give a single clear derivation, the safest conclusion is that Ong is a short surname with uncertain origin, likely arising through abbreviation, spelling reduction, or local surname development.
History
The name appears in old surname indexes and dictionaries, but usually as a brief variant or cross-reference rather than a fully explained headword. In modern English-speaking countries it is comparatively uncommon, and today it is often found among families of East and Southeast Asian origin as well as in some European lineages where the spelling may reflect a shortened or anglicized form.
Origin
Regions
Variant spellings
Fun fact
In genealogy databases, Ong often turns up as a spelling that can belong to very different family histories, so the surname alone is not enough to identify a single origin.
From the historical record
“Hemy. On his marriage to a lady of quality he trausj)osed this appellation to Heniy l-ong, and became the founder of the Longs of Wiltshire. Camden. The H.R. forms of the name are Lougus, Le Long, and Le Longe. ^^ LONG. A component syllable of many”
— Patronymica Britannica: a dictionary of the family names of the United Kingdom