The actor-comic, who had been hospitalized for pneumonia this month, died of unconfirmed causes at Northwestern Memorial hospital.
"It brought tears to my eyes because Bernie Mac has always been my all-time favorite entertainer and comedian. It pains me to have to report that," said Sun-Times columnist Stella Foster.
The comedian's sudden death comes in the wake of a statement from his publicist, Danica Smith, who said Thursday that Mac's condition had stabilized.
Smith had repeatedly denied that Mac's bout of pneumonia was related to a pre-diagnosed inflammatory lung disease the actor suffered from, the Sun-Times said.
People magazine said the actor, whose real name was Bernard McCullough, is survived by his wife, Rhonda McCullough; a daughters, Je'Niece; and a granddaughter, Jasmine.