Ke$ha Olsen Twin?

1/7/2010 5:44 PM PST BY TMZ STAFF
Here's bubblegum pop newbie Ke$ha -- the chick who sings that "Tik Tok" song you can't get out of ya head -- at some event in NYC last month (left) and wonder twin Mary-Kate Olsen a few months ago (right).

Ke$ha and Mary-Kate
So far, only one has been to rehab.

We're just sayin'.