Police officers are retiring in historic numbers — and the exodus will only accelerate if anti-cop Democratic Mayoral nominee Zohran Mamdani is elected, union officials warned this week.

As of Monday, 1,555 NYPD officers put in their papers — 48% more than the 1,049 who retired last year, and 65% more than a decade ago, when just 941 turned in their shields, according to NYPD data provided to The Post by the Police Benevolent Association.

Union leaders weren’t aware of any time in history that retirements for the first six months of year were as high, and worry about the disastrous affect the lefty Mamdani could have on NYPD recruitment and retention.

“We can’t afford to have a mayor who ignores the problem or tries to take us backward,” said PBA President Patrick Hendry. “We need a mayor who will speak up for police officers, and treat us and pay us like the professionals we are.”