One woman pedestrian was killed and another was critically injured in separate hit-and-run crashes in Queens and Brooklyn overnight, police said.

In the deadly incident, a 31-year-old woman was mowed down by a white sedan at 97th Avenue and 121st Street in Richmond Hill at about 2:45 a.m. Saturday, the NYPD said. The woman suffered massive body trauma. She was taken to Jamaica Medical Center, where she was pronounced dead.

The callous driver took off. There were no arrests.

First responder broadcasts said investigators were looking for a white Nissan with front end damage.

Shortly before the deadly incident, four men were slashed in a fight just two blocks away, sources and cops said. Police are investigating whether that violence — details were not immediately available — is linked to the hit-and-run, the NYPD said.

In Brooklyn, a woman bicyclist was critically injured after she was struck by a black SUV while attempting to cross the intersection of New York Avenue and Cortelyou Road in Flatbush at about 11:10 p.m. Friday, police said.

The unidentified woman in her 30s was taken to Kings County Hospital. The driver of the SUV sped off and there were no arrests, the NYPD said Saturday morning.