The current mayor of the city, Michael Bloomberg, led the tributes to someone he described as "a great mayor, a great man, and a great friend".
He said: "In elected office and as a private citizen, he was our most tireless, fearless, and guileless civic crusader.
"Through his tough, determined leadership and responsible fiscal stewardship, Ed helped lift the city out of its darkest days and set it on course for an incredible comeback. We will miss him dearly."
A staunch supporter of Israel, Mr Koch turned his back on President Barack Obama in 2011 over his Middle East polices and endorsed a Republican contender for a local congressional seat.
