The columnist mocked Watson for simultaneously being an unapologetic feminist and appearing in a candid shot wearing a see-through top.
The picture was part of a photo series by US magazine Vanity Fair. Watson is this month’s cover star.
Hartley-Brewer posted a picture of the Sun newspaper’s coverage, which splashed a shot of the former Harry Potter star it described as “topless” on page three.
“Emma Watson: ‘Feminism, feminism... gender wage gap... why oh why am I not taken seriously... feminism... oh, and here are my tits!’”
The accusation angered many, with people piling in to censure Hartley-Brewer.
Hartley-Brewer tackled some of her critics head-on.
She was backed up by other social media users, including James Delingpole, a regular Breibart contributor.
Watson starred for a special edition of Vanity Fair to promote her upcoming film ‘Beauty and the Beast’, a remake of the classic Disney tale in which she plays Belle.