Ramsey, who is highly respected within CPD where he worked for 30 years, will help reform the department as they grapple with the aftermath of recent police shootings.
"I think the city of Chicago, the police department will benefit from Chuck Ramsey's experience at going through two efforts with the Justice Department in Washington and Philadelphia, but more importantly with deep roots here in Chicago," Mayor Rahm Emanuel said on Sunday.
Ramsey, who will earn $350 an hour as a senior advisor to CPD, is well known to the department. He came up through the ranks in Chicago, rising all the way up to deputy superintendent before moving on to Washington, D.C., and then Philadelphia.
At one point, Ramsey had called the CPD superintendent position his dream job. However, in the last month, he has publicly said he would like to stay retired and only plans to act as a consultant to CPD.
"Commissioner Ramsey is a not only a national leader in urban policing who has led two major police departments through civil rights reforms - he is also a native Chicagoan who knows our police department and our communities. With roots in Englewood, he has a unique understanding of the important role community relationships play in making our city safer," Emanuel said.
Ramsey, an African-American from the city's South Side, returns to Chicago amid protests that have called for Emanuel to resign over the release two months ago of the video of Laquan McDonald's shooting death by Officer Jason Van Dyke. The video sparked the biggest crisis of Emanuel's administration and cost Police Superintendent Garry McCarthy his job.
"The situation in Chicago is not unlike many cities across the country, but the people of Chicago should know that their leaders are working hard to restore trust where it has been lost," Ramsey said in a statement.
What kind of recommendations he will make is unclear, but last month he said that he wanted state police in Pennsylvania to head investigations of police-involved shootings in Philadelphia.
Ramsey has more than 40 years of law enforcement experience. He began his career in 1968 as a cadet in the Chicago Police Department and served in the department for the next 30 years. He served as Chicago's Commander of the Narcotics Division, Deputy Chief of the Patrol Division and Deputy Superintendent from 1994 to 1998. He played a key role in creating and implementing the Chicago Alternative Policing Strategy.
He served as Chief of the Metropolitan Police Department of the District of Columbia from 1998 to 2007, then as the Commissioner of the Philadelphia Police Department from 2007 until his retirement in 2015.
"Commissioner Ramsey's return to the Chicago Police Department is an opportunity to build on the important work we are undertaking to restore trust between the Department and Chicago's residents," said Acting Chicago Police Superintendent John Escalante. "I look forward to relying on his counsel and leadership."
On the same day as the announcement, an anti-violence group organized a march and rally outside the Chicago police headquarters on the South Side.
The hiring doesn't impress those on the front lines of the protests against CPD. Neither do the mayor's other announced reforms.
"I blame Rahm for part of this black on black violence as well because if these kids had jobs and resources," said activist Lamon Reccord. "They wouldn't be killing each other. You can't kill each other if you're at work."
Also on Sunday, an outdoor police roll call was held in the city's Woodlawn neighborhood, one of many CPD plans to hold in the community - an effort to respond to community calls to be more visible.
"We just want to engage the community even more and make them a partner of CPD," Eddie Johnson, chief of patrol for CPD.
The Associated Press contributed to this report.