Engineers at Nasa's Jet Propulsion Laboratory in California commanded the twin spacecraft, Ebb and Flow, to fire their engines and burn their remaining fuel. Ebb plunged first, followed by Flow.
Afterwards Nasa said it had dedicated the spot in honour of mission team member Sally Ride, the first American woman in space, who died earlier this year.
By design, the impact site was far away from the Apollo landings and other historical sites.
Ms Ride's sister, who was in the control room for the finale, said it might be time to dust off Ms Ride's first telescope to view the site.
"We can look at the moon with a new appreciation and a smile when we see it, knowing that a little corner is named after Sally," the Rev Bear Ride said.
Since the crashes occurred on the moon's dark side, they were not visible from Earth. The Lunar Reconnaissance Orbiter will pass over the mountain and attempt to photograph the skid marks left by the washing machine sized-spacecraft as they hit the surface at 3800mph.
After rocketing off the launch pad in September 2011, Ebb and Flow took a roundabout journey to the moon, arriving over the New Year's holiday. They focused on measuring the moon's gravity field in a bid to learn more about its interior and early history.
After flying in formation for months, they produced the most detailed gravity maps of any body in the solar system.
Scientists expect to sift through data and images from the mission for years.