It’s a good day to be a part of the itty bitty committee!

Lady Gaga, Mandy Moore, Kaitlyn Dever, Elizabeth Olsen and Thuso Mbedu all wowed at Sunday’s Critics Choice Awards in plunging necklines that showcased lots of clavicle and breasts that conformed to the laws of gravity regardless of size.

There was nary a fantasy pushup bra in sight.

“The plunging necklines are a classic eveningwear glamour statement,” Kathlin Argiro, a designer and Fashion Institute of Technology professor, told The Post.

This time, though, the stars embracing the look let their natural shapes take center stage — and didn’t allow smaller cup sizes stop them from daring to bare.

Argiro said this change reflects a “seismic shift in fashion,” with the classic cut being modeled by a range of women — from 25-year-old Kathryn Newton to 48-year-old Kristen Wiig.

“I can’t imagine it doesn’t have to do with confidence,” Argiro added.

They’re not the only ladies diving into the trend. Rather, they’re supported by the growing movement of women ditching bras all together or opting for softer, wire-free numbers, which now outsell their uncomfortably rigid counterparts, according to a recent report from market research group NPD.

The trend ramped up during the pandemic and appears to be here to stay. Per NPD, women are increasingly trading in their waist cinchers and bodysuits for more easygoing tank tops and thongs.

And when they do dress up, women of all sizes are more likely to accentuate their natural shapes, donning pieces with plunging necklines and drastic cutouts or made of yards of sheer fabric.

“Breasts are accessories,” Kimmay Caldwell, an undergarment expert, told The Post.

In her 17 years of bra fitting, Caldwell has seen many changes in how women want to shape and display their breasts.

She’s noticed a recent swing toward body acceptance — influenced in part by living braless at home for two years.

Caldwell said that many women simply don’t want to shape their bodies in uncomfortable and unnatural ways.

“Women are always told we’re either too much or not enough,” Caldwell said.

And smaller-busted fashionistas amping up the sex appeal in deep-cut dresses is just one aspect of women freeing themselves from the constraints of outmoded fashion decrees.

Susanna Moyer, a fashion consultant in New York City, agreed that fashion’s “biggest trend is body positivity and really showing off what you feel comfortable with.”

“People are becoming realistic,” Moyer told The Post.