Sebastian

Also Estonian: https://www.stat.ee/nimed/Sebastian

Also Venetian: https://vec.wikipedia.org/wiki/San_Sebastian_(santo)

Also Gascon, Provençal and Languedocian: https://ieo-oc.org/spip.php?page=article&id_article=290 --- Source: Institut d'Estudis Occitans

I'd just like to point out that it's a very cliche name for butlers in Japanese comics and animation. They even parody it.

In 2018, 4 is the most common age for an American (U.S.) Sebastian who is registered male with the Social Security Administration. It is the 624th most common male first name for living U.S. citizens.

A nickname for the Portuguese form of this name ("Sebastião") is "Batião."

Also used in Croatia.

Also used in Sweden. In 2006 it was ranked 33. [noted -ed]

Sebastian is the Czech and Slovak form.
Name Day: 20th January (in the Czechia).
Nicknames: Seb, Sebby, Sebas, Bastian, Basty.

Also a masculine name in Slovenia.

Slovenes are crazy about foreign names so please don't write for each name that appears in Slovenia - "Also used in Slovenia."

Given the history of St. Sebastian as a figure of homoerotic art, Sebastian seems to be a name used frequently for gay characters, as seen in Brideshead Revisited, Suddenly Last Summer, and Little Britain.

The name is very popular in Germany.

Also used in Romania. [noted -ed]