Parent company Avid Life Media, which operates the infidelity network, said it and CEO Noel Biderman were in "mutual agreement" about the split.
"This change is in the best interest of the company and allows us to continue to provide support to our members and dedicated employees," Avid Life Media said.
The firm, meanwhile, is "adjusting to the attack on our business and members' privacy by criminals," the company added, vowing uninterrupted member access to its website.
Other senior managers will step in to fill the gap left by Biderman's departure until a new boss is appointed, the firm said.
A hacker group calling itself the "Impact Team" last week released emails and user account information of members stolen from the company's servers, as well as corporate emails and sensitive computer source code.
The gang claimed it wanted to bring attention to the fact that Ashley Madison was charging clients a fee to delete their personal information but was in fact archiving it.
Canadian police have said two possible suicides, including one by a Texas police officer, may be linked to the leak of the website's 32 million members' personal data.
The breach has also stirred concern the potential for blackmail. Privacy watchdogs in Canada and Australia are jointly investigating the leak.
Police in Toronto, where Avid Life Media is based, along with the Royal Canadian Mounted Police, the Ontario Provincial Police, US Homeland Security, the Pentagon and the American FBI are also probing the most talked-about hack of the year.
Calling it "one of the largest data breaches in the world," Toronto police Staff Superintendent Bryce Evans told a press conference last Monday it "will continue to have a longterm social and economic impact."
He warned of "spin offs of crimes and further victimization" including extortion attempts.
Although there has been no measurable uptick in business for divorce lawyers, Internet reputation and public relations consultants said their phones have been ringing off the hook from cheaters in crisis seeking help.
Celebrity casualties include Josh Duggar, the 27-year-old star of a Christian family reality TV show who has blown nearly $1,000 on two Ashley Madison accounts since February 2013.
However, an analysis of the leaked data by news site Gizmodo showed little if any activity from the purported 5.5 million female members of Ashley Madison, who were online with an estimated 31 million male subscribers.
The data, which was released on the "dark web" and is not easily accessible to most Internet users, suggests the vast majority of profiles of women on Ashley Madison were fake, or created by automated "bots."
Gizmodo traced many of the IP addresses for females back to Ashley Madison itself. The most popular female last name on the site also matches the name of a former employee.
Avid Life Media has declined to comment on the report.
But if true, the data would suggest the website facilitated very few extramarital affairs.
Avid Life Media is offering a Can$500,000 ($375,000) reward for information leading to the arrest of the hackers.
In turn it is being sued by a disabled Canadian widower who says he joined Ashley Madison "in search of companionship" after losing his wife of 30 years to breast cancer.
source: www.abs-cbnnews.com
