Gillett
A surname usually understood as a French diminutive of Gilles, the French form of Giles, though some English families may have separate baptismal origins.
The #6,421 most common surname in the United States (2010 Census) — about 1 in every 58,331 Americans shares it.
Etymology
Most authorities connect Gillett with French Gillot, a diminutive of Gilles, the French form of Giles. In that reading, the name ultimately goes back to the Latin name Aegidius, meaning something like "young goat" in a classical sense, though the surname itself came through medieval French naming habits rather than directly from Latin. Older writers also noted that some English spellings in Gillett/Gillot may have been influenced by the same baptismal root as William-related names, so the history is not entirely simple.
History
19th-century surname dictionaries commonly place Gillett among French names brought into England by immigrant families and later naturalized there. Lower specifically notes established English families spelling the name Gillett and Gillot, especially in places such as Glastonbury, Exeter, and Banbury. Because related spellings overlap with other forms, some bearers may descend from more than one historical source line.
Origin
Regions
Variant spellings
Fun fact
Lower remarks that Gillett and Gillot were already well-established in England by the 19th century, not just rare bookish spellings.
From the historical record
“a derivation of Guillaume, William. GILLETT. See Gillet. GILLIAM. See William. GILLIATT. See William. GILLIE, A menial servant. Jaraicson. GILLIES. Gael. Gille Jesa, the Ser- vant or Follower of Jesus ; " a youth under the protection of Jesus." .Johnstoue'.s Anecd. of Olave the Black. 1780.”
— Patronymica Britannica: a dictionary of the family names of the United Kingdom