Jin-sun Kim announced at an executive staff meeting that he is stepping down from his role with PyeongChang Organising Committee (POCOG) at what he believes is a key time in the planning for the event.
He said in a speech: "PyeongChang 2018 is at a turning point for the latter half of its Games preparation, which requires more detailed planning and execution.
"At this critical juncture, I believe that PyeongChang 2018 needs new leadership and a stronger system that will effectively carry out various Games-related projects. And this is why I decided to resign as President of POCOG."
Kim had been due to remain in the role until October 2015 after securing a new two-year term last October.
No announcement has been made on a replacement for the outgoing president.