Is this guy interested or not?

Honestly, it's difficult to say. Don't get your hopes up, but start talking to him. I know it's easier said than done. But you don't want to waste the opportunity to find out. Smile when he looks at you, small things like that. If you get a bad reaction after talking and everything, then you'll know better for the next time. If not, you get a hunky new boyfriend. What's to lose?