Fraud was in fashion for a blonde beauty who swindled a New Jersey philanthropist for more than half a million bucks, he claims in a lawsuit.

Brittany Rawlings, 34, buddied up to much-older hedge-funder Lawrence Salameno and his wife, Theresa, after meeting the Mahwah couple’s son in 2013.

A lawyer specializing in the fashion industry, Rawlings spent years “ingratiating” herself, pitching her idea for FashionBoss, a company that would help fashion designers get off the ground.

The Salamenos started forking over cash as ground-floor investors in FashionBoss, meeting Rawlings for lunches and dinners as she claimed to be hiring employees, issuing stock and soliciting other investors to serve “thousands” of clients.

Instead, Rawlings was using the Salamenos’ money “to keep up her active social life in the Miami party scene,” they charge in their Manhattan Federal Court lawsuit.

She pegged the “retired, beneficent and trusting” pair for her “long con,” milking them for $561,000 over five years before she disappeared, they charge.

Well known for their philanthropy in their home state, including donations to Ramapo College where a spiritual center is named for them, the Salamenos say Rawlings gave them official-looking documents like a “tactical content production plan request for funds.”

FashionBoss never got out of “beta testing,” and Rawlings changed the company name to SmartBoss, continuing to milk the Salamenos for funds until August 2017, when she showed up looking “uncharacteristically disheveled” for dinner with the couple.

She insisted they’d all be “celebrating their success together soon,” but then Rawlings vanished, ignoring overtures from the Salamenos.

They finally heard from her in February when she wrote to them, claiming SmartBoss had been hacked and comparing “her own suffering over SmartBoss to that of a mother suffering over a still-born baby,” the Salamenos said in court papers seeking unspecified damages.

“There’s not an ounce of validity to any of their claims,” said Rawlings’ lawyer, Jonathan Davidoff, who said his client, her family and other investors lost far more than the Salamenos.