In 2012, the property tycoon sent seven tweets over a period of around a month in which he urged Ms Stewart’s former partner, Robert Pattinson, to break off his relationship with her.
In one tweet, the now-President said she had cheated on Mr Pattinson "like a dog".
“He was mad at me a couple years ago, really obsessed with me a couple years ago, which is f****ing crazy,” she told Variety.
Ms Stewart said she had not paid much attention to the reality star at the time, but the comments have since taken on new significance.
Speaking about her stance on the newly-elected President, she said: “I've never been the most politically charged person, but I think at this point, it's not political, it’s f**king so humanitarian.”
Among other celebrities, Mr Trump has also used Twitter to address pop star Katy Perry.
During 2014 he repeatedly urged her to break up with comedian Russell Brand.
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