The skimpy swimwear, designed by Melissa Odabash, has a legion of celebrity fans in its adult sizes, but the range for little girls, sold exclusively on mum-of-two Paltrow's website, has led to accusations of sexualising children.
Billed as 'exclusive kids New York bikini set', the £30 two piece is sold as being a desirable designer beachwear for a mum and me look.
'We've collaborated with Melissa Odabash on several exclusive (and super cute) beachwear items for girls', the blurb reads, 'Now your daughter can have a Melissa Odabash bikini too. Hers is navy with ruffles on the top and bottom, and ties on the back and sides. 4, 6 and 8 year old sizing'.
"We remain very opposed to the sexualisation of children and of childhood," he said. "The dangers have been discussed at length, so it is a great pity that such trends continue and that they carry celebrity endorsement."
Paltrow launched Goop in 2008 and has faced criticism for its content before. Last month, she was slated for her spring wardrobe tips, which would have cost readers £301,556 to achieve.
A spokesperson for Miss Paltrow blasted the current round of criticism as 'absurd'. "Two-piece bathing suits have been worn by young girls for decades," he said.
What do you think? Would you buy a bikini for your little girl?
More on Parentdish: Gloop (in homage to Gwyneth Paltrow)