Orland Park police said officers responded to a 911 call about a body inside a home in the 14100-block of Concord Drive around 6:30 p.m. Wednesday.
There, officers found 77-year-old Samir Kassem, who was pronounced dead on the scene. Police did not immediately say how he died.
After an initial investigation, police identified the victim's son, Ibrahim Kassem, as a person of interest.
Officers found the 46-year-old and took him into custody. He is now charged with first-degree murder, police said.
He is due in court at the Leighton Criminal Courthouse on Saturday.
Authorities did not immediately provide further information.