St Clair
A surname from the place-name and title “St. Clair,” ultimately tied to a French locale and adopted as a family name by people linked to that name.
The #2,469 most common surname in the United States (2010 Census) — about 1 in every 21,161 Americans shares it.
Etymology
St Clair is a surname taken from a place-name, most famously the Norman baronial name de St Clair. The name ultimately refers to a locality called Saint-Clair in France, a name built from the Christian saint’s name and the Latin clearus, meaning “bright” or “clear.” In English use, the surname often appears as St Clair, St. Clair, or Sinclair, the last being a long-established contracted form.
History
The name came to Britain with Norman families after the Conquest and became established in Scottish and English history, especially through the influential St Clair or Sinclair line. Over time, the form Sinclair became more common in everyday use, while St Clair remained as a less contracted spelling. In North America, both spellings survive, often reflecting family preference or later standardization.
Origin
Regions
Variant spellings
Fun fact
St Clair and Sinclair are historically connected: Sinclair is often the contracted English form of the same Norman surname.