She’s the Coco Chanel of bank robbers, darling.

A woman wearing an oversize striped chapeau, sunglasses and fuzzy white slippers looked like she was headed to Bridgehampton polo yesterday.

Instead, she was on her way to rob a bank in the laid-back village of Westhampton Beach, LI, police said.

The chic thief sashayed into Astoria Federal Savings, on Sunset Avenue near Hansen Place, at 9 a.m. and handed the teller a note demanding cash.

The compliant employee forked over an undetermined amount to the bizarre crook, who then bolted out a back door, cops said.

The woman, described as black and 35 to 45 years of age, was last seen fleeing behind a 7-Eleven down the block.

“Oh, my God! It was mayhem here,” a rattled witness told The Post.