It's National Bubble Bath Day and Hollywood is getting in on the action ... by climbing in the tub!!!

Ricky Martin, Jack Black, Karin Jinsui and the Clermont twins are a sampling of the celebs getting some R&R with a little hot water and some suds ... and they all look hot.

Reality TV star Harry Jowsey is having some fun in the tub ... rocking a bubble beard.

Yeah, he's too hot to handle ... in the tub or out.

Take it from Sonja Morgan, the best way to unwind from a long, hard day of being a 'Real Housewife' ... a bubble bath, of course.

Still feelin' dirty?!? Rinse off with these babes in the shower!!!