It’s “The Fountainhead” meets The Dunderhead.

On the very morning Mayor Bill de Blasio announced his presidential bid, his office tweeted a quote from the late conservative author and philosopher Ayn Rand — then promptly removed the posting.

“’I would give the greatest sunset in the world for one sight of New York’s skyline.’ — Ayn Rand. Get excited: Today will be another gorgeous day—a high of 72 degrees and sunny,” reads the tweet, posted at 7:10 a.m. Thursday by the @NYCMayorsOffice Twitter account.

The tweet was deleted later Thursday morning, but Hizzoner’s office could not provide a reason for the change of heart.

Social media users were quick to point out the deep irony in de Blasio — who is trying to frame himself as the progressive champion to take down President Trump — quoting an author who Trump has cited as influential.

“On the day @BilldeBlasio announces his run for the @WhiteHouse, @NYCMayorsOffice tweets out a quote from Ayn Rand! Got to love the irony,” one person tweeted, along with a screenshot of the since-deleted posting by the mayor’s office.

The “Atlas Shrugged” author’s personal philosophy of Objectivism — which preaches laissez-faire capitalism and “the virtue of selfishness” — espoused in her novels is like literary erotica for the far-right, even though it has found little purchase among academic philosophers.

“It relates to business (and) beauty (and) life and inner emotions. That book relates to … everything,” Trump once said of Rand’s “The Fountainhead,” whose protagonist is an anti-establishment skyscraper architect.

The mayor’s office did not respond to a request for comment and would not say which of Rand’s books is de Blasio’s favorite.