Is there any built-in behavior for Command + Delete (delete line right of cursor) in macOS? It is possible to press ⎇ Backspace on macOS in order to delete the previous word (left of the cursor), and ⌘ Backspace to delete the previous line (left of the cursor). If you have an external keyboard with a "delete" key (or the "forward delete key"), or are able to emulate the delete key via software, it is possible to press ⎇ Delete to delete the word to the right of the cursor. However, perhaps surprisingly, it is not possible to press ⌘ Delete in order to delete the line to the right of the cursor.

Now, I have only been able to make this possible by emulating a ⌘⇧→ and then a Backspace with BetterTouchTool. However, I want to avoid doing something like this because BTT does not work at a "low enough level" for me – that is to say, the action is not entirely reliable.

Is there any official macOS way to delete the line to the right of the cursor?
Apparently, macOS Supports Emacs style shortcuts...

What you are looking for is this: Control + K

Technically by holding the fn button with the backspace you get the actual Delete key, but on my mac at least it doesn't allow forward delete to the end of the line, but the above shortcut does.

This should work but doesn't:
fn + Command + Backspace

However you've got an answer now...

Source: Apple Questions