Billy
A surname that can be French and locational in origin, and in English also appears as a nickname from the familiar form of William.
The #9,027 most common surname in the United States (2010 Census) — about 1 in every 85,265 Americans shares it.
Etymology
The strongest historical note in the sources points to a French place-name origin: Lower says Billy is not from William, but from a place in the arrondissement of Caen, in Normandy. Other evidence shows that Billy was also felt in English as a nickname form connected with William, since later writers gloss it as a form like 'Little Billy' and record it in playful nickname use. Because both explanations appear in the historical material, the surname is best treated cautiously as having either a French locational source or an English nickname association, depending on the family line.
History
The name appears in British surname discussions as a French import, especially from Normandy, and similar place-derived surnames often entered England after medieval contact with Norman families. In later English usage, Billy also became an obvious familiar form of William, which helped it survive in nickname and comic usage. The surname is relatively uncommon in the modern United States.
Origin
Regions
Variant spellings
Fun fact
A 1913 surname book explicitly notes that 'Little Billy' can mean Wilmot, showing how easily French and English naming traditions could blur together.
From the historical record
“above. BILLY. N'otfrom'\Yilliam,butfrom aplace in thearroudissementof Caen, inNormandj'. Also a comrade, compaiuon. Jamiesou. BILNEY. Parishes in Norfolk, BILTON. Places in cos. York and Wai-wick. BINDLOOSE. This contradictory- looking name, formerly written B3'mllos, is probably local.”
— Patronymica Britannica: a dictionary of the family names of the United Kingdom