John Schnatter quits as chairman after using racial slur during a conference call on how to handle controversial situations.
Ritchie reassures customers that Schnatter's words do not reflect his views or the values of the company.
A special committee of independent directors ordered the termination of a so-called founder's agreement that designated Schnatter as the brand's face and voice and is requesting he cease media appearances on behalf of the firm, the company said in a statement after a Sunday night board meeting.
Ritchie, who has been with Papa John's since 1996, was promoted from president to CEO following another Schnatter-related scandal in which the founder blamed the chain's poor earnings on the National Football League's failure to quell players' silent on-field protests during the singing of the national anthem.
Schnatter also came under fire in 2012 for saying the Affordable Care Act could be "lose-lose" for Papa John's franchisees and employees.
"I will personally be leading this effort because there is nothing more important for Papa John's right now".
"We will be engaging a broad set of stakeholders to chart a course forward that demonstrates our commitment to diversity, equity and inclusion", he said.
He pointed out that Schnatter's type of behavior would not be tolerated from any employee at Papa John's. "But I never apologized for taking the name down and I never knew about it". Eventually, Pizza Hut took over as the new official pizza sponsor, though Papa John's still had agreements with 22 teams at that time.
Stone: Think I'm probably person in indictment
The indictment refers to a USA person who "was in regular contact with senior members of the presidential campaign of Donald J. Those documents were then publicized by two online channels, a site called DCLeaks and a persona known as Guccifer 2.0.