The post was sparked after a Facebook user named Geoff took offence to Barry's off-the-shoulder top, so the presenter made sure to post a photo of herself in a strapless swimsuit.
He wrote on the Seven Sharp page: "Please encourage Hilary to dress properly. Exposed shoulders are for the young."
Barry responded to the comment in an Instagram post, writing: "Some classic age shaming from Geoff. Just for the record, I'll wear what I like, when I like."
Her followers loved the post.
Bachelorette Lily McManus commented: "YESSSSSSSSSSS MUMMA".
Her TVNZ colleagues weather presenter Renee Wright and newsreader Melissa Stokes also posted their messages of support.
Barry has regularly taken a stand for women who are told by men to "cover up" after being the subject of viewer complaints who take offence to her wardrobe choices.
In April Barry joked about her "#newscleave" while posting a photo of herself in her 21st dress for her #FormalFriday challenge.
"This #formalfriday I give you the outfit my mum made for me for my 21st. Seems I was fond of #newscleave even back in 1990," she wrote.
Last year a disgruntled viewer named Barbara made a complaint to Seven Sharp with the subject header "Hilary's cleavage" in which she claimed to have been "assailed" by Barry's preference for plunging necklines and choice of chesty clothing.
"It's a fact of nature that women's breasts are sex objects and should be kept private except for at the beach or at an evening do."
Barry's response let viewers know that she wasn't having a bar of it.
"Well here's the thing Barbara, I'm just a middle-aged mother of two who slapped on some lippy and a pretty top to look presentable for the nation," she said.