3.3v and 5v supply shared Ground?

Hey, Sorry I'm an idiot or whatever,

Faster to ask here then crawl through the dox looking,

Can I hook up a 3.3v and 5v circuit, and use the same ground to return them?
You have to right?

(Just looking for 1 person to gimmie confidence it'll work, then ff to delete thread)

Yes, the 3.3V and 5V supplies on the Arduino use the same Ground Reference.