New Lenox Deputy Chief Robert Pawlisz said officers found Fisk, 64, behind the wheel late Monday with an open bottle of vodka on the truck's floor.
"He was behind the wheel unconscious," Pawlisz said.
Fisk was taken to a hospital for treatment and released from custody after posting bail, Pawlisz said. He has a court appearance scheduled for Nov. 29 in Will County.
Besides the DUI charge, he faces charges of lane-use violation and illegal transportation of alcohol.
New Lenox is about 35 miles southwest of downtown Chicago.
Fisk became part of an unforgettable baseball moment while playing for the Boston Red Sox when he belted a 12th-inning home run that won Game 6 of the 1975 World Series.
Fisk played 11 seasons with the Red Sox and 13 with the Chicago White Sox.