Authorities responded to the accident on US-41 North just north of Vincennes at 1:28 a.m. A man, identified as Albert Kennedy of Vincennes, was declared dead at the scene.
Investigators say the pedestrian walked out in the middle of the roadway and was struck by the bus. Aldean was on the bus at the time of the accident.
"In all the years I've been touring and all the miles we've driven, nothing prepares you for something like this to happen," Aldean said in a statement posted on Twitter. "I'm praying for Albert Kennedy's family and friends today and ask that you do the same."
The accident remains under investigation.