Principal shareholder Dermot Desmond paid tribute to “all he has given” to Celtic over so many years.
He pointed out that Lawwell had overseen the building of their training centre at Lennoxtown, the creation of the new facility at Barrowfield, and the upgrading of Celtic Park during his time at the club.
“I am personally very sorry to lose Peter, but I understand and respect his decision in light of recent events and what he has endured,” Desmond said.
“As chief executive, Peter was the driving force of the club and, in his later role as chairman, he oversaw board affairs.
“Peter has witnessed 38 cup or title triumphs in his time at the club, a period of extraordinary domestic dominance for us as we have also competed in European football.”
Chief executive Michael Nicholson added that it “is a sad day for Celtic” and that “the abuse and threats” directed towards Lawwell and his family “are completely unacceptable”.
Non-executive director Brian Wilson will become interim chairman from 31 December until a permanent appointment is made.
