You spell Katie in Hebrew like this:
קייטי
This is the direct English to Hebrew translation of the name, although it is not necessarily the Hebrew version of the name Katie.
This is because Katie is not a Hebrew name and so it can only be translated into the closest possible version of a Hebrew name.
If you want to translate Katie into the Hebrew version of the name, you will get the name “Kati”. Once again, this is only a close translation and not a direct one.
If you would like to find out how to write this and other names in Hebrew, you can turn to sites like My Hebrew Name.
To find out how to say the name Katie out loud, in Hebrew, simply click on this link and use the “listen” button.