Niklaus is the Swiss German and Flemish form of Nicholas, from the Greek Nikolaos, meaning "victory of the people" (nikē + laos). Ranked #1232 with a peak in 2021 and around 2,300 total SSA uses, it's the specific spelling associated with the German-speaking cantons of Switzerland and with a certain vampire in American television.
Swiss German Roots and the Nicholas Family
Nicholas took different forms across Europe as it spread from Greek through Latin and into vernacular languages: Nikolaus in German, Nikolaas in Dutch, Nikola in Slavic languages, Nicolas in French and Spanish. Niklaus is distinctly Swiss German — the form you'd find in Canton Bern or Zurich — and also used in Belgium's Flemish region. German names in this family tradition carry the full weight of Nicholas's extraordinary history as Saint Nicholas of Myra, the basis for Santa Claus, and one of the most venerated saints in both Eastern and Western Christianity.
The Vampire Diaries Effect
Niklaus Mikaelson, known as "Klaus," is the central antagonist-turned-antihero of The Vampire Diaries and its spinoff The Originals. His full name Niklaus was used ceremonially in the show, and the character's enormous fan following in the early 2010s directly contributed to the name's American visibility. The 2021 peak in SSA data lands exactly at the distance you'd expect from parents who were fans of the show in their teens watching it in the early 2010s, now having children.
Klaus vs. Niklaus: The Full Form Question
Most families drawn to this name probably intend for Klaus to be the daily name, with Niklaus as the formal birth certificate version. That's a reasonable approach. Klaus alone is more recognizable and carries its own five-letter crispness. Niklaus gives the full formal option without requiring the child to explain the spelling daily, since Klaus is standard as a nickname and understood as such.