Gillam
A surname usually tied to the name William, with some early forms also reflecting French Guillaume.
The #9,003 most common surname in the United States (2010 Census) — about 1 in every 84,984 Americans shares it.
Etymology
Gillam is generally treated as a surname formed from the medieval pet form of William, especially Gill or Gille, with the final element reflecting a later surname ending. Historical spellings in the sources include forms such as Gyllan, Gilliam, and Gillam, which fit this pattern well. Some early references also point to Guillaume, the Norman French form of William, as part of the background.
History
The name appears in medieval records in several spellings, especially in Yorkshire and later in London parish registers. Over time it settled into the modern form Gillam, while related surnames such as Gillham and Gilliam remained alongside it. The sources also suggest that some bearers may have been recorded through occupational or servant-like bynames in older records, but the main origin is patronymic.
Origin
Regions
Variant spellings
Fun fact
Some 19th-century surname writers linked Gillam directly to William, showing how a familiar given name could generate several different surnames.
From the historical record
“is no reasoo for doubting its con- nexion with William. For eariier instances, v, Gillam. 1605. Bapt — William, a. RIcbard Gyllan. : Si. Ju. ClerltenwelL i. 46. 1773. UacTted — Samael GilHiam and”
— A Dictionary of English and Welsh Surnames, with special American instances