A newborn girl was found abandoned behind a building in a Queens housing project last night, police said.

The child, only one or two days old, was discovered 11:30 p.m. in a grassy area in the Woodside Houses after passersby heard her crying.

“I heard a baby crying and somebody yelling ‘there’s a baby behind the building,’ ’’ said Essence Shepherd.

The baby, who appeared to be in good health, was taken to Elmhurst Hospital.