Are you supposed to do a disk clean up before you defrag?

I just did a clean install of windows today and I put alot of favorites and stuff on my pc. I have very little memory at the moment. I'll be adding some soon, but I was just looking around and decided to anylse my C drive. for defrag. It said that I should. Befor I do it should I run disk clean up? I want to conserve as much of my memory that I can.