Boy · Name family
Caius
6,513births recorded
9Countries
3Variants
2014Peak · British Columbia
#683Alberta 2025
Caius is a boy name family recorded 6,513 times in 9 countries since 1925. It ranks highest today in Alberta (#683 in 2025). Its all-time peak was in British Columbia in 2014, at 65.6 births per 100,000. Elsewhere it is mostly given as Kajus (England & Wales, Ireland, Northern Ireland), Kaius (Ontario).
Popularity by country
Births per 100,000 newborns, all forms of the name combined.
Which form wins where
Births per 100,000 newborns for each form, in the selected country.
All forms of Caius
| Variants | Language | Total births | Country | Latest rank | Peak year | 10-year trend |
|---|---|---|---|---|---|---|
| Caius | English | 2,329 | 🇺🇸 United States | #927 | 2025 | ▲ 105 % |
| Caius | English | 496 | 🏴 England & Wales | #976 | 2023 | ▲ 100 % |
| Caius | English | 100 | 🇨🇦 Ontario | #1033 | 2020 | ▲ 63 % |
| Caius | English | 73 | 🇨🇦 Alberta | #683 | 2015 | ▼ 33 % |
| Caius | English | 48 | 🇨🇦 British Columbia | – | 2014 | – |
| Caius | English | 6 | 🏴 Scotland | – | 2011 | – |
| Kaius | English | 2,011 | 🇺🇸 United States | #1028 | 2025 | ▲ 120 % |
| Kaius | English | 260 | 🏴 England & Wales | #1197 | 2022 | ▲ 73 % |
| Kaius | English | 118 | 🇨🇦 Ontario | #907 | 2023 | ▲ 30 % |
| Kaius | English | 39 | 🇨🇦 Alberta | #683 | 2023 | ▲ 35 % |
| Kaius | English | 35 | 🇨🇦 British Columbia | – | 2014 | – |
| Kajus | English | 739 | 🏴 England & Wales | #1406 | 2013 | ▼ 52 % |
| Kajus | English | 189 | 🇮🇪 Ireland | – | 2010 | – |
| Kajus | English | 35 | 🇬🇧 Northern Ireland | – | 2012 | – |
| Kajus | English | 17 | 🇺🇸 United States | – | 2004 | – |
| Kajus | English | 13 | 🏴 Scotland | – | 2018 | – |
How we grouped these names
- Caius ↔ Kajus — Wikidata “said to be the same as”
- Caius ↔ Kaius — spelling variant
Questions about Caius
How popular is the name Caius?
In 2025 it ranked #683 in Alberta. Official registers record 6,513 births across 9 countries.
What is Caius in other languages?
Kaius (English); Kajus (English).
When was Caius most popular?
It peaked in British Columbia in 2014, at 65.6 births per 100,000.
Is Caius a boy or a girl name?
In official birth registers, Caius is a boy name.