Duchess Kate, who is expecting her second child with Prince William, took 29 per cent of the total, with mum-of-six Angelina securing 17 per cent.
Holly recently welcomed her third child with husband Dan Baldwin, a little boy called Chester William. The happy couple are also parents to Harry, five, and three-year-old Belle.
Katie Hilton, a healthcare associate for breastfeeding experts Lansinoh – who conducted the poll – believes Holly's appeal is because UK mothers can relate to her.
"The survey results suggest that mums in the UK relate to down-to-earth celebrity mothers over glamorous, Hollywood celebrities," Katie said.
"Her role on This Morning means that Holly Willoughby is somebody that mums wake up with in the morning when we are getting the kids ready for school or nursery.
"She comes across as very grounded and unpretentious, and mums like to talk to other women that can relate to."
The survey wasn't just carried out in the UK; women across the world were asked the same question, from Brazil and France to Germany and Mexico.
Angelina topped the poll in seven of the nine countries - although not in her home land of the USA.
That honour went to mum-of-three Jennifer Garner, with 26 per cent of the vote, followed by Jessica Alba, with 23 per cent.