A 51-year-old woman was fatally struck by a driver on the Upper East Side early Monday, cops said.

The slain pedestrian — whose name has not been released pending family notification — was in the crosswalk at East 76th Street and Third Avenue just after 6:30 a.m. when she was struck by an Audi sedan, according to cops and police sources.

She was pronounced dead at the scene, authorities said.

The motorist, a 59-year-old woman, remained on the scene and was not charged.

No criminality was immediately suspected, cops said.