This is not the dream this Mad Avenue ad woman dreamed.

Perfume-company ad director Laura Ziv says her boss relentlessly harassed her about her looks and weight — and was especially cruel in saying she looked like the matronly “Britain’s Got Talent” sensation Susan Boyle.

Boyle, a stout Scot, made international waves with her rendition of “I Dreamed a Dream” from “Les Misérables” in 2009.

In a $6 million Manhattan Supreme Court lawsuit, filed yesterday, Ziv, 45, of Princeton, NJ, alleges manager Herve Pierini unleashed the verbal assaults at the Madison Avenue and East 59th Street headquarters for the scent maker Firmenich.

The abuse was so severe, she claims, she suffered a brain hemorrhage from the stress.

She’s suing Pierini and Firmenich.

Ziv claims Pierini targeted her after she refused to build a competing fragrance brand with him — on company time.

“In January 2010, Pierini taunted Ziv at a party given by an executive of the [company’s] biggest client at her home by repeatedly referring to Ziv as ‘Susan Boyle,’ a Scottish singer who is often taunted in the media as being old, fat and ugly,” the suit says.

Pierini’s insults became more direct after the Boyle comparison.

“On one occasion when a fellow employee did not take the time for lunch, Pierini remarked to Ziv, in the presence of other employees and for them to hear, ‘Not like you, fatty,’ ” according to legal papers.

And later, Pierini gestured toward Ziv during an office party and said, “Fatty here is having a cupcake.”

The married mother of two young children says her boss dropped her from the company’s biggest account and took away a promised bonus — after she again refused to help him launch a competing startup.

Ziv’s attorney wrote to the CEO of Firmenich in June after his client took a medical leave.

The company’s attorneys did not believe the accusations, according to the suit, and responded that Ziv would lose her salary and benefits. Ziv has not been fired.

Neither Pierini nor Firmenich returned messages seeking comment.

Additional reporting by Laurel Babcock