Rennie
A Scottish surname usually understood as a diminutive of Reynold or Reginald, though some sources also linked it to the French name René.
The #8,133 most common surname in the United States (2010 Census) — about 1 in every 75,747 Americans shares it.
Etymology
Most historical surname dictionaries treat Rennie as a Scottish diminutive of Reynold or Reginald, with the ending -ie used to make an affectionate or smaller form. Those personal names go back to Germanic elements meaning roughly “rule” and “counsel,” so the underlying sense is “little Reynold/Reginald” rather than a separate independent word. A few older writers also suggested a connection with René, but that is a minority explanation and not the usual one for the surname.
History
The name is especially associated with Scotland, where it appears as a familiar diminutive surname and also as a variant of forms like Renney and Renny. In later reference works it is commonly cross-referenced under Reynolds or Reginald rather than treated as an independent root. It is also well known as a given name and family name in Scotland and the Scottish diaspora.
Origin
Regions
Variant spellings
Fun fact
Some 19th-century writers debated whether Rennie should be linked to Reynold/Reginald or to the French name René, but the Germanic diminutive explanation is the standard one in surname dictionaries.
From the historical record
“RENNICK for Renwick, q.v. RENNIE, a North, double dim. of fieynold, Reginald, q.v. [E. dim. suff. -ie] RENSHALL for Renshaw, q.v. RENSHAW (Eng.) Dweller at the Raven- Wood or Raven's Wood [O.E. hrafn, a raven + sc{e)ag(f, a wood] Stephen de Ravenshagh. — Lane. Fines, A.D. 1342.”
— Surnames of the United Kingdom: a concise etymological dictionary (2 vols in 1)