Meaning and Name Origin
Guillemette \gu(i)-lle-mette\ as a girls' name. Guillemette's root is Old German, and Guillemette means "determined protector". Guillemette is a derivative of Wilhelmina (Old German): the second element of the source phrase literally refers to a helmet. An unusual birth name.
Guillemette is an unusual first name for females but a very prominent last name for all people (#13050 out of 88799, Top 15%). (2000 U.S. Census)
Shown below is a comparison of the popularity of the girl name Guillemette and affiliated names. The only popular variation form of Guillemette (#unlisted) ranked in the Top 1000 is Wilhelmina. Adoption of this girl name was at its highest during 1880-1889 and is now much lower, with the form Wilhelmina becoming less in vogue. (2014 Birth Statistics)