Tidjane Thiam is set to step down months after it emerged that two former employees of the Zurich-based company had been placed under surveillance.
The bank’s chief operating officer Pierre-Olivier Bouée resigned in October after admitting he arranged for private detectives to snoop on former head of wealth management Iqbal Khan, who had left to join rivals UBS.
Last month Credit Suisse announced an internal investigation had concluded a second former top executive was also spied on.
Announcing his resignation on Friday, Mr Thiam said he had “no knowledge of the observation of two former colleagues” but acknowledged the scandal “undoubtedly disturbed Credit Suisse and caused anxiety and hurt”.
“I regret that this happened and it should never have taken place,” he added.
Mr Thiam will depart the company on 14 February, after the presentation of Credit Suisse’s fourth-quarter results. He will be replaced by Thomas Gottstein, the chief executive of the bank’s Swiss operations.
The head of Credit Suisse’s global security services also quit over the spying scandal last year.
The bank’s investigation found Mr Bouée had arranged the surveillance of Mr Khan to see if he was trying to poach employees or clients.
Private detectives snooped on him from 4-17 September, when he realised he was being followed and confronted one of them in the street.
Credit Suisse’s subsequent probe found no evidence that Mr Thiam knew anything about the surveillance operations, the bank said.
Mr Thiam, who is from Cote d’Ivoire, became the bank’s first African-born chief executive when he was appointed to the role in 2015.
Last month, he was one of about two dozen business leaders who dined with US president Donald Trump at the World Economic Forum’s annual summit in Davos, Switzerland.
His resignation was accepted unanimously by Credit Suisse’s board.
Chairman Urs Rohner paid tribute to Mr Thiam’s “enormous contribution” to the bank, adding: “It is to his credit that Credit Suisse is standing on a very solid foundation and has returned successfully to profit.”
The 164-year-old bank, which is perhaps best known for its wealth management and investment banking operations, has more than 45,000 employees and had assets worth nearly 1.35 trillion Swiss francs (£1.07 trillion) under management as of the end of 2018.
Additional reporting by agencies