Chien
A surname of French origin, based on the word for “dog,” sometimes used as a nickname or perhaps from a place-name.
The #8,732 most common surname in the United States (2010 Census) — about 1 in every 82,201 Americans shares it.
Etymology
In French, chien means “dog,” from Latin canis. As a surname, it may have begun as a nickname, perhaps for someone thought dog-like in appearance, temper, or habits, or it may in some cases reflect a local or regional name that happened to include the same word. The historical sources you provided strongly support the French word itself, but they do not firmly establish one single surname pathway for every family named Chien.
History
Medieval and early modern French naming often drew on animal terms as nicknames, and the word chien appears in older surname and byname material in that broader pattern. The form is uncommon as a hereditary surname today and is found in several modern communities, including some bearers in the United States, but the deeper family histories may differ from one line to another. Because the excerpted sources are incidental rather than a direct headword entry, the historical explanation should be treated cautiously.
Origin
Regions
Variant spellings
Fun fact
Old French surname collections also record several dog-based nicknames, showing how common animal imagery was in medieval bynames.
From the historical record
“Geoftrei' le Ken. B. Resioaid le Chien, C R., 14 Bdw. I. (9) Local, ' of Kenn,' a parish in CO. Somerset, ten miles from Axbridge.”
— A Dictionary of English and Welsh Surnames, with special American instances