Ireland Baldwin has no support -- no bra, no bikini top, no nothing -- but the good news is she's the new poster child for the "Free the Nipple" movement.

Ireland hit up the beach in Malibu Thursday for a ridiculously hot photo shoot. The 21-year-old posed in a vintage, see-through dress -- in and out of the water. She also slipped into a wet muscle tank. What we're saying is ... the girl's got range.

And a smoking bod to match. Viva la movement!

BEACH BUM
MEGA