How to write Isaac in Japanese
In Japan, Isaac is written in katakana: アイザック, pronounced “aizakku”. That's the spelling to use on a form, a name tag, or when you introduce yourself.
The kanji above are ateji — characters picked because they sound like the name. There's no single official version, so go with the one whose meaning you like best.
Isaac in kanji, character by character
More names in Japanese
Kanji meanings from KANJIDIC2 © EDRDG (CC BY-SA 4.0).