A Nassau County police horse named for a fallen officer clip-clopped into retirement on Monday as his namesake’s widow looked on.

Mike, a black Percheron mix in his early 20s, was led out of the Mounted Unit’s stable in Eisenhower Park in East Meadow before dozens of saluting cops, plus department Commissioner Patrick Ryder.

His namesake, Officer Michael Califano, was sitting in his patrol cruiser during a traffic stop on the Long Island Expressway when the car was struck from behind by a flatbed truck in February 2011.

The flatbed mounted the cruiser’s roof, crushing Califano, 44, beneath its massive weight. By the time rescuers were able to free the 12-year department vet, it was too late.

But Califano’s name lived on as Mike kept order at presidential debates and other high-profile events.

The horse will be adopted by a loving family, the department said.

“He’s gonna be missed,” Califano’s widow, Jackie told News 12 Long Island. “It just means a lot that my husband was remembered this way.”