Guidice previously served as the head of OEMC before becoming Mayor Johnson's chief of staff.
In a statement, the mayor said, "For more than three decades, Rich Guidice has admirably served the City of Chicago, earning tremendous respect under four mayors and across multiple City departments. From West Side roots and the halls of Gordon Tech High School, to leadership through some of Chicago's most remarkable major events, Rich has long been a steady and guiding force, and a mentor to many.
"To come out of retirement to serve in my administration is a testament to his belief in our work and our vision for the City of Chicago, and for that, I am grateful.
"Our administration is better because of the time he spent as my chief of staff, and I wish him good health, good fortune, and the absolute best in a hard-earned and very well-deserved retirement."
Guidice's final day will be on April 1.