The self-titled 'Covid-compliant' gathering, organised by fans group, The Celtic Trust, went ahead despite both Celtic and Police Scotland urging supporters not to attend.
A large banner proclaiming 'Back the team, sack the board' was displayed outside the stadium while Celtic Trust chairman Jeanette Findlay addressed the crowd.
"The board, who are responsible for all of this, whose job it is to make sure we have a successful team on the park, have had nothing to say," she stated. "Absolutely nothing.
"They have not been listening. They can see what we can see but instead of coming forward with a contingency plan, they have said nothing.
"The first time they had anything to say, was to criticise supporters for coming and protesting.”
Celtic fans have protested for the departure of manager Neil Lennon but have also turned their anger towards majority shareholder Dermot Desmond and chief executive Peter Lawwell after falling 16 points behind Rangers in their quest to win a record-setting 10th consecutive title.
"You've got nothing to apologise for and you are here to support your team,” Ms Findlay added. "If you want change, then we, the fans' body, has to take control of this club."
The Celtic Trust Twitter account (@TheCelticTrust) also posted: “A huge thanks to all the supporters who came out in their hundreds in torrential rain to hold the PLC Board to account and to show their backing for the team. Impeccable behaviour as usual.”