Free the nipple!

Selena Gomez turned heads on #NoBraDay when she wore a black top with nothing underneath.

RELATED: See 12 Celebs Who Love Going Sans Support in Honor of #NoBraDay!

The 23-year-old actress turned up the heat with a black mini-skirt and black heels, amping up her sex appeal.

#NoBraDay was created as an event to raise awareness for Breast Cancer Awareness Month, encouraging people to ditch their bras for the day to support survivors.

Click through the gallery above to see more of Selena's nipple-y moments!