Coach Cesare Prandelli, who on Monday was forced to drop Domenico Criscito after the left back was warned by police that he was being probed in a fix investigation, whittled his squad down from 25 ahead of UEFA's deadline for the June tournament.
Inter centre back Ranocchia's exclusion means Bonucci could well start their Euro 2012 Group C opener against holders Spain in Gdansk on June 10.
Bonucci's name has been mentioned in testimony during the match-fixing probe but he has not been formally put under investigation and has denied wrongdoing.
The Italian football federation has said it is happy with the Juventus defender's inclusion.
Asked about Italy's match-fixing crisis, Spain coach Vicente del Bosque told a news conference in Berne on Tuesday: "What has happened in Italy leaves me with a very bad taste. I did not like it at all.
"It's an extremely damaging episode for football but there is a parallel industry to this sport that you can't control.
"I won't get into whether it will benefit us or not. What I do know is that the Italian players are professional athletes and they will go out there (against Spain) with the intention of winning."
Italy will also face Croatia and Ireland at the finals being co-hosted by Ukraine and Poland.
Goalkeepers: Gianluigi Buffon (Juventus), Morgan De Sanctis (Napoli), Salvatore Sirigu (Paris St Germain)
Defenders: Ignazio Abate (AC Milan), Federico Balzaretti (Palermo), Andrea Barzagli (Juventus), Leonardo Bonucci (Juventus), Giorgio Chiellini (Juventus), Christian Maggio (Napoli), Angelo Ogbonna (Torino)
Midfielders: Daniele De Rossi (Roma), Alessandro Diamanti (Bologna), Emanuele Giaccherini (Juventus), Claudio Marchisio (Juventus), Riccardo Montolivo (Fiorentina), Thiago Motta (Paris St Germain), Antonio Nocerino (AC Milan), Andrea Pirlo (Juventus)
Forwards: Mario Balotelli (Manchester City), Fabio Borini (Roma), Antonio Cassano (AC Milan), Antonio Di Natale (Udinese), Sebastian Giovinco (Parma)