Justin Bieber -- He's a Kippah!

10/4/2010 2:40 PM PDT BY TMZ STAFF
Justin Bieber threw on his finest yarmulke and went to the wedding of his musical director in Toronto over the weekend.

Oy, he looks so skinny. He should really eat something.

100110_bieber_video4UPDATE: Bieber also joined forces with the groom (who played guitar) to rock "Baby" for crowd ... it's definitely worth a watch.