Which Confident Celeb Flaunted Her Toned Bikini Body to Millions of Twitter Followers? (PHOTOS)

Summer may be over, but celebs never shy away from showing off their beach-ready bodies, weather be damned!

This spunky pop singer took a bathroom self portrait while sporting an absolutely adorable (and itsy bitsy) polka dot bikini. But who is she? Click through the gallery to find out!