Paris St German president Alain Cayzac saw his offer to resign promptly accepted by the crisis-hit side here on Monday.
PSG, one of the French league's flagship teams, are going through their worst ever crisis with relegation to the second division looming in the coming weeks.
With four league games remaining PSG - who have won the League Cup and are in the French Cup semi-finals - sit 18th in the 20-team first division, just above already-relegated Metz and three points behind fourth from bottom Lens.
The bottom three teams in the French top flight drop to the second tier.
Cayzac's resignation comes a day after a crisis meeting between Cayzac, majority shareholder Sebastien Bazin and coach Paul Le Guen, and two days after PSG's 3-0 defeat to Caen.
On Sunday several PSG players' cars were attacked by irate supporters, some of whom have also spray-painted threats on walls at the club's training ground at Saint-Germain-en-Laye.
Le Guen, who arrived at the club before the start of the season following a disastrous spell with Scottish Premier League leaders Rangers, may yet follow suit.
Former PSG coach Luis Fernandez has been touted as a possible replacement for Le Guen, if he leaves the club.