Bisoli, 44, was dismissed earlier on Tuesday following the 2-0 loss to Udinese on Sunday.
The Rossoblu club currently sit bottom of Serie A having picked up one point in their opening five games.
"As of today, Stefano Pioli is the new coach of Bologna," the club confirmed in a statement.
"Pioli has signed a two-year contract and will be unveiled to the media tomorrow (Wednesday)."
The 45-year-old was sacked by Palermo after a short period with the club as President Maurizio Zamparini felt there was "no confidence in him".
Pioli will have some time to settle in to his new post because of the upcoming international break. His first game in charge will be at Novara on October 16.